More on Leadership

Aniket
3 years ago
Yahoo could have purchased Google for $1 billion
Let's see this once-dominant IT corporation crumble.
What's the capital of Kazakhstan? If you don't know the answer, you can probably find it by Googling. Google Search returned results for Nur-Sultan in 0.66 seconds.
Google is the best search engine I've ever used. Did you know another search engine ruled the Internet? I'm sure you guessed Yahoo!
Google's friendly UI and wide selection of services make it my top choice. Let's explore Yahoo's decline.
Yahoo!
YAHOO stands for Yet Another Hierarchically Organized Oracle. Jerry Yang and David Filo established Yahoo.
Yahoo is primarily a search engine and email provider. It offers News and an advertising platform. It was a popular website in 1995 that let people search the Internet directly. Yahoo began offering free email in 1997 by acquiring RocketMail.
According to a study, Yahoo used Google Search Engine technology until 2000 and then developed its own in 2004.
Yahoo! rejected buying Google for $1 billion
Larry Page and Sergey Brin, Google's founders, approached Yahoo in 1998 to sell Google for $1 billion so they could focus on their studies. Yahoo denied the offer, thinking it was overvalued at the time.
Yahoo realized its error and offered Google $3 billion in 2002, but Google demanded $5 billion since it was more valuable. Yahoo thought $5 billion was overpriced for the existing market.
In 2022, Google is worth $1.56 Trillion.
What happened to Yahoo!
Yahoo refused to buy Google, and Google's valuation rose, making a purchase unfeasible.
Yahoo started losing users when Google launched Gmail. Google's UI was far cleaner than Yahoo's.
Yahoo offered $1 billion to buy Facebook in July 2006, but Zuckerberg and the board sought $1.1 billion. Yahoo rejected, and Facebook's valuation rose, making it difficult to buy.
Yahoo was losing users daily while Google and Facebook gained many. Google and Facebook's popularity soared. Yahoo lost value daily.
Microsoft offered $45 billion to buy Yahoo in February 2008, but Yahoo declined. Microsoft increased its bid to $47 billion after Yahoo said it was too low, but Yahoo rejected it. Then Microsoft rejected Yahoo’s 10% bid increase in May 2008.
In 2015, Verizon bought Yahoo for $4.5 billion, and Apollo Global Management bought 90% of Yahoo's shares for $5 billion in May 2021. Verizon kept 10%.
Yahoo's opportunity to acquire Google and Facebook could have been a turning moment. It declined Microsoft's $45 billion deal in 2008 and was sold to Verizon for $4.5 billion in 2015. Poor decisions and lack of vision caused its downfall. Yahoo's aim wasn't obvious and it didn't stick to a single domain.
Hence, a corporation needs a clear vision and a leader who can see its future.
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Jason Kottke
3 years ago
Lessons on Leadership from the Dancing Guy
This is arguably the best three-minute demonstration I've ever seen of anything. Derek Sivers turns a shaky video of a lone dancing guy at a music festival into a leadership lesson.
A leader must have the courage to stand alone and appear silly. But what he's doing is so straightforward that it's almost instructive. This is critical. You must be simple to follow!
Now comes the first follower, who plays an important role: he publicly demonstrates how to follow. The leader embraces him as an equal, so it's no longer about the leader — it's about them, plural. He's inviting his friends to join him. It takes courage to be the first follower! You stand out and dare to be mocked. Being a first follower is a style of leadership that is underappreciated. The first follower elevates a lone nut to the position of leader. If the first follower is the spark that starts the fire, the leader is the flint.
This link was sent to me by @ottmark, who noted its resemblance to Kurt Vonnegut's three categories of specialists required for revolution.
The rarest of these specialists, he claims, is an actual genius – a person capable generating seemingly wonderful ideas that are not widely known. "A genius working alone is generally dismissed as a crazy," he claims.
The second type of specialist is much easier to find: a highly intellectual person in good standing in his or her community who understands and admires the genius's new ideas and can attest that the genius is not insane. "A person like him working alone can only crave loudly for changes, but fail to say what their shapes should be," Slazinger argues.
Jeff Veen reduced the three personalities to "the inventor, the investor, and the evangelist" on Twitter.

Looi Qin En
3 years ago
I polled 52 product managers to find out what qualities make a great Product Manager
Great technology opens up an universe of possibilities.
Need a friend? WhatsApp, Telegram, Slack, etc.
Traveling? AirBnB, Expedia, Google Flights, etc.
Money transfer? Use digital banking, e-wallet, or crypto applications
Products inspire us. How do we become great?
I asked product managers in my network:
What does it take to be a great product manager?
52 product managers from 40+ prominent IT businesses in Southeast Asia responded passionately. Many of the PMs I've worked with have built fantastic products, from unicorns (Lazada, Tokopedia, Ovo) to incumbents (Google, PayPal, Experian, WarnerMedia) to growing (etaily, Nium, Shipper).
TL;DR:
Soft talents are more important than hard skills. Technical expertise was hardly ever stressed by product managers, and empathy was mentioned more than ten times. Janani from Xendit expertly recorded the moment. A superb PM must comprehend that their empathy for the feelings of their users must surpass all logic and data.
Constant attention to the needs of the user. Many people concur that the closer a PM gets to their customer/user, the more likely it is that the conclusion will be better. There were almost 30 references to customers and users. Focusing on customers has the advantage because it is hard to overshoot, as Rajesh from Lazada puts it best.
Setting priorities is invaluable. Prioritization is essential because there are so many problems that a PM must deal with every day. My favorite quotation on this is from Rakuten user Yee Jie. Viki, A competent product manager extinguishes fires. A good product manager lets things burn and then prioritizes.
This summary isn't enough to capture what excellent PMs claim it requires. Read below!
What qualities make a successful product manager?
Themed quotes are alphabetized by author.
Embrace your user/customer
Aeriel Dela Paz, Rainmaking Venture Architect, ex-GCash Product Head
Great PMs know what customers need even when they don’t say it directly. It’s about reading between the lines and going through the numbers to address that need.
Anders Nordahl, OrkestraSCS's Product Manager
Understanding the vision of your customer is as important as to get the customer to buy your vision
Angel Mendoza, MetaverseGo's Product Head
Most people think that to be a great product manager, you must have technical know-how. It’s textbook and I do think it is helpful to some extent, but for me the secret sauce is EMPATHY — the ability to see and feel things from someone else’s perspective. You can’t create a solution without deeply understanding the problem.
Senior Product Manager, Tokopedia
Focus on delivering value and helping people (consumer as well as colleague) and everything else will follow
Darren Lau, Deloitte Digital's Head of Customer Experience
Start with the users, and work backwards. Don’t have a solution looking for a problem
Darryl Tan, Grab Product Manager
I would say that a great product manager is able to identify the crucial problems to solve through strong user empathy and synthesis of insights
Diego Perdana, Kitalulus Senior Product Manager
I think to be a great product manager you need to be obsessed with customer problems and most important is solve the right problem with the right solution
Senior Product Manager, AirAsia
Lot of common sense + Customer Obsession. The most important role of a Product manager is to bring clarity of a solution. Your product is good if it solves customer problems. Your product is great if it solves an eco-system problem and disrupts the business in a positive way.
Edward Xie, Mastercard Managing Consultant, ex-Shopee Product Manager
Perfect your product, but be prepared to compromise for right users
AVP Product, Shipper
For me, a great product manager need to be rational enough to find the business opportunities while obsessing the customers.
Janani Gopalakrishnan is a senior product manager of a stealth firm.
While as a good PM it’s important to be data-driven, to be a great PM one needs to understand that their empathy for their users’ emotions must exceed all logic and data. Great PMs also make these product discussions thrive within the team by intently listening to all the members thoughts and influence the team’s skin in the game positively.
Director, Product Management, Indeed
Great product managers put their users first. They discover problems that matter most to their users and inspire their team to find creative solutions.
Grab's Senior Product Manager Lakshay Kalra
Product management is all about finding and solving most important user problems
Quipper's Mega Puji Saraswati
First of all, always remember the value of “user first” to solve what user really needs (the main problem) for guidance to arrange the task priority and develop new ideas. Second, ownership. Treat the product as your “2nd baby”, and the team as your “2nd family”. Third, maintain a good communication, both horizontally and vertically. But on top of those, always remember to have a work — life balance, and know exactly the priority in life :)
Senior Product Manager, Prosa.AI Miswanto Miswanto
A great Product Manager is someone who can be the link between customer needs with the readiness and flexibility of the team. So that it can provide, build, and produce a product that is useful and helps the community to carry out their daily activities. And He/She can improve product quality ongoing basis or continuous to help provide solutions for users or our customer.
Lead Product Manager, Tokopedia, Oriza Wahyu Utami
Be a great listener, be curious and be determined. every great product manager have the ability to listen the pain points and understand the problems, they are always curious on the users feedback, and they also very determined to look for the solutions that benefited users and the business.
99 Group CPO Rajesh Sangati
The advantage of focusing on customers: it’s impossible to overshoot
Ray Jang, founder of Scenius, formerly of ByteDance
The difference between good and great product managers is that great product managers are willing to go the unsexy and unglamorous extra mile by rolling up their sleeves and ironing out all minutiae details of the product such that when the user uses the product, they can’t help but say “This was made for me.”
BCG Digital Ventures' Sid Narayanan
Great product managers ensure that what gets built and shipped is at the intersection of what creates value for the customer and for the business that’s building the product…often times, especially in today’s highly liquid funding environment, the unit economics, aka ensuring that what gets shipped creates value for the business and is sustainable, gets overlooked
Stephanie Brownlee, BCG Digital Ventures Product Manager
There is software in the world that does more harm than good to people and society. Great Product Managers build products that solve problems not create problems
Experiment constantly
Delivery Hero's Abhishek Muralidharan
Embracing your failure is the key to become a great Product Manager
DeliveryHero's Anuraag Burman
Product Managers should be thick skinned to deal with criticism and the stomach to take risk and face failures.
DataSpark Product Head Apurva Lawale
Great product managers enjoy the creative process with their team to deliver intuitive user experiences to benefit users.
Dexter Zhuang, Xendit Product Manager
The key to creating winning products is building what customers want as quickly as you can — testing and learning along the way.
PayPal's Jay Ko
To me, great product managers always remain relentlessly curious. They are empathetic leaders and problem solvers that glean customer insights into building impactful products
Home Credit Philippines' Jedd Flores
Great Product Managers are the best dreamers; they think of what can be possible for the customers, for the company and the positive impact that it will have in the industry that they’re part of
Set priorities first, foremost, foremost.
HBO Go Product Manager Akshay Ishwar
Good product managers strive to balance the signal to noise ratio, Great product managers know when to turn the dials for each up exactly
Zuellig Pharma's Guojie Su
Have the courage to say no. Managing egos and request is never easy and rejecting them makes it harder but necessary to deliver the best value for the customers.
Ninja Van's John Prawira
(1) PMs should be able to ruthlessly prioritize. In order to be effective, PMs should anchor their product development process with their north stars (success metrics) and always communicate with a purpose. (2) User-first when validating assumptions. PMs should validate assumptions early and often to manage risk when leading initiatives with a focus on generating the highest impact to solving a particular user pain-point. We can’t expect a product/feature launch to be perfect (there might be bugs or we might not achieve our success metric — which is where iteration comes in), but we should try our best to optimize on user-experience earlier on.
Nium Product Manager Keika Sugiyama
I’d say a great PM holds the ability to balance ruthlessness and empathy at the same time. It’s easier said than done for sure!
ShopBack product manager Li Cai
Great product managers are like great Directors of movies. They do not create great products/movies by themselves. They deliver it by Defining, Prioritising, Energising the team to deliver what customers love.
Quincus' Michael Lim
A great product manager, keeps a pulse on the company’s big picture, identifies key problems, and discerns its rightful prioritization, is able to switch between the macro perspective to micro specifics, and communicates concisely with humility that influences naturally for execution
Mathieu François-Barseghian, SVP, Citi Ventures
“You ship your org chart”. This is Conway’s Law short version (1967!): the fundamental socio-technical driver behind innovation successes (Netflix) and failures (your typical bank). The hype behind micro-services is just another reflection of Conway’s Law
Mastercard's Regional Product Manager Nikhil Moorthy
A great PM should always look to build products which are scalable & viable , always keep the end consumer journey in mind. Keeping things simple & having a MVP based approach helps roll out products faster. One has to test & learn & then accordingly enhance / adapt, these are key to success
Rendy Andi, Tokopedia Product Manager
Articulate a clear vision and the path to get there, Create a process that delivers the best results and Be serious about customers.
Senior Product Manager, DANA Indonesia
Own the problem, not the solution — Great PMs are outstanding problem preventers. Great PMs are discerning about which problems to prevent, which problems to solve, and which problems not to solve
Tat Leong Seah, LionsBot International Senior UX Engineer, ex-ViSenze Product Manager
Prioritize outcomes for your users, not outputs of your system” or more succinctly “be agile in delivering value; not features”
Senior Product Manager, Rakuten Viki
A good product manager puts out fires. A great product manager lets fires burn and prioritize from there
acquire fundamental soft skills
Oracle NetSuite's Astrid April Dominguez
Personally, i believe that it takes grit, empathy, and optimistic mindset to become a great PM
Ovo Lead Product Manager Boy Al Idrus
Contrary to popular beliefs, being a great product manager doesn’t have anything to do with technicals, it sure plays a part but most important weapons are: understanding pain points of users, project management, sympathy in leadership and business critical skills; these 4 aspects would definitely help you to become a great product manager.
PwC Product Manager Eric Koh
Product managers need to be courageous to be successful. Courage is required to dive deep, solving big problems at its root and also to think far and dream big to achieve bold visions for your product
Ninja Van's Product Director
In my opinion the two most important ingredients to become a successful product manager is: 1. Strong critical thinking 2. Strong passion for the work. As product managers, we typically need to solve very complex problems where the answers are often very ambiguous. The work is tough and at times can be really frustrating. The 2 ingredients I mentioned earlier will be critical towards helping you to slowly discover the solution that may become a game changer.
PayPal's Lead Product Manager
A great PM has an eye of a designer, the brain of an engineer and the tongue of a diplomat
Product Manager Irene Chan
A great Product Manager is able to think like a CEO of the company. Visionary with Agile Execution in mind
Isabella Yamin, Rakuten Viki Product Manager
There is no one model of being a great product person but what I’ve observed from people I’ve had the privilege working with is an overflowing passion for the user problem, sprinkled with a knack for data and negotiation
Google product manager Jachin Cheng
Great product managers start with abundant intellectual curiosity and grow into a classic T-shape. Horizontally: generalists who range widely, communicate fluidly and collaborate easily cross-functionally, connect unexpected dots, and have the pulse both internally and externally across users, stakeholders, and ecosystem players. Vertically: deep product craftsmanship comes from connecting relentless user obsession with storytelling, business strategy with detailed features and execution, inspiring leadership with risk mitigation, and applying the most relevant tools to solving the right problems.
Jene Lim, Experian's Product Manager
3 Cs and 3 Rs. Critical thinking , Customer empathy, Creativity. Resourcefulness, Resilience, Results orientation.
Nirenj George, Envision Digital's Security Product Manager
A great product manager is someone who can lead, collaborate and influence different stakeholders around the product vision, and should be able to execute the product strategy based on customer insights, as well as take ownership of the product roadmap to create a greater impact on customers.
Grab's Lead Product Manager
Product Management is a multi-dimensional role that looks very different across each product team so each product manager has different challenges to deal with but what I have found common among great product managers is ability to create leverage through their efforts to drive outsized impacts for their products. This leverage is built using data with intuition, building consensus with stakeholders, empowering their teams and focussed efforts on needle moving work.
NCS Product Manager Umar Masagos
To be a great product manager, one must master both the science and art of Product Management. On one hand, you need have a strong understanding of the tools, metrics and data you need to drive your product. On the other hand, you need an in-depth understanding of your organization, your target market and target users, which is often the more challenging aspect to master.
M1 product manager Wei Jiao Keong
A great product manager is multi-faceted. First, you need to have the ability to see the bigger picture, yet have a keen eye for detail. Secondly, you are empathetic and is able to deliver products with exceptional user experience while being analytical enough to achieve business outcomes. Lastly, you are highly resourceful and independent yet comfortable working cross-functionally.
Yudha Utomo, ex-Senior Product Manager, Tokopedia
A great Product Manager is essentially an effective note-taker. In order to achieve the product goals, It is PM’s job to ensure objective has been clearly conveyed, efforts are assessed, and tasks are properly tracked and managed. PM can do this by having top-notch documentation skills.
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Jari Roomer
3 years ago
Successful people have this one skill.
Without self-control, you'll waste time chasing dopamine fixes.
I found a powerful quote in Tony Robbins' Awaken The Giant Within:
“Most of the challenges that we have in our personal lives come from a short-term focus” — Tony Robbins
Most people are short-term oriented, but highly successful people are long-term oriented.
Successful people act in line with their long-term goals and values, while the rest are distracted by short-term pleasures and dopamine fixes.
Instant gratification wrecks lives
Instant pleasure is fleeting. Quickly fading effects leave you craving more stimulation.
Before you know it, you're in a cycle of quick fixes. This explains binging on food, social media, and Netflix.
These things cause a dopamine spike, which is entertaining. This dopamine spike crashes quickly, leaving you craving more stimulation.
It's fine to watch TV or play video games occasionally. Problems arise when brain impulses aren't controlled. You waste hours chasing dopamine fixes.
Instant gratification becomes problematic when it interferes with long-term goals, happiness, and life fulfillment.
Most rewarding things require delay
Life's greatest rewards require patience and delayed gratification. They must be earned through patience, consistency, and effort.
Ex:
A fit, healthy body
A deep connection with your spouse
A thriving career/business
A healthy financial situation
These are some of life's most rewarding things, but they take work and patience. They all require the ability to delay gratification.
To have a healthy bank account, you must save (and invest) a large portion of your monthly income. This means no new tech or clothes.
If you want a fit, healthy body, you must eat better and exercise three times a week. So no fast food and Netflix.
It's a battle between what you want now and what you want most.
Successful people choose what they want most over what they want now. It's a major difference.
Instant vs. delayed gratification
Most people subconsciously prefer instant rewards over future rewards, even if the future rewards are more significant.
We humans aren't logical. Emotions and instincts drive us. So we act against our goals and values.
Fortunately, instant gratification bias can be overridden. This is a modern superpower. Effective methods include:
#1: Train your brain to handle overstimulation
Training your brain to function without constant stimulation is a powerful change. Boredom can lead to long-term rewards.
Unlike impulsive shopping, saving money is boring. Having lots of cash is amazing.
Compared to video games, deep work is boring. A successful online business is rewarding.
Reading books is boring compared to scrolling through funny videos on social media. Knowledge is invaluable.
You can't do these things if your brain is overstimulated. Your impulses will control you. To reduce overstimulation addiction, try:
Daily meditation (10 minutes is enough)
Daily study/work for 90 minutes (no distractions allowed)
First hour of the day without phone, social media, and Netflix
Nature walks, journaling, reading, sports, etc.
#2: Make Important Activities Less Intimidating
Instant gratification helps us cope with stress. Starting a book or business can be intimidating. Video games and social media offer a quick escape in such situations.
Make intimidating tasks less so. Break them down into small tasks. Start a new business/side-hustle by:
Get domain name
Design website
Write out a business plan
Research competition/peers
Approach first potential client
Instead of one big mountain, divide it into smaller sub-tasks. This makes a task easier and less intimidating.
#3: Plan ahead for important activities
Distractions will invade unplanned time. Your time is dictated by your impulses, which are usually Netflix, social media, fast food, and video games. It wants quick rewards and dopamine fixes.
Plan your days and be proactive with your time. Studies show that scheduling activities makes you 3x more likely to do them.
To achieve big goals, you must plan. Don't gamble.
Want to get fit? Schedule next week's workouts. Want a side-job? Schedule your work time.

Yogesh Rawal
3 years ago
Blockchain to solve growing privacy challenges
Most online activity is now public. Businesses collect, store, and use our personal data to improve sales and services.
In 2014, Uber executives and employees were accused of spying on customers using tools like maps. Another incident raised concerns about the use of ‘FaceApp'. The app was created by a small Russian company, and the photos can be used in unexpected ways. The Cambridge Analytica scandal exposed serious privacy issues. The whole incident raised questions about how governments and businesses should handle data. Modern technologies and practices also make it easier to link data to people.
As a result, governments and regulators have taken steps to protect user data. The General Data Protection Regulation (GDPR) was introduced by the EU to address data privacy issues. The law governs how businesses collect and process user data. The Data Protection Bill in India and the General Data Protection Law in Brazil are similar.
Despite the impact these regulations have made on data practices, a lot of distance is yet to cover.
Blockchain's solution
Blockchain may be able to address growing data privacy concerns. The technology protects our personal data by providing security and anonymity. The blockchain uses random strings of numbers called public and private keys to maintain privacy. These keys allow a person to be identified without revealing their identity. Blockchain may be able to ensure data privacy and security in this way. Let's dig deeper.
Financial transactions
Online payments require third-party services like PayPal or Google Pay. Using blockchain can eliminate the need to trust third parties. Users can send payments between peers using their public and private keys without providing personal information to a third-party application. Blockchain will also secure financial data.
Healthcare data
Blockchain technology can give patients more control over their data. There are benefits to doing so. Once the data is recorded on the ledger, patients can keep it secure and only allow authorized access. They can also only give the healthcare provider part of the information needed.
The major challenge
We tried to figure out how blockchain could help solve the growing data privacy issues. However, using blockchain to address privacy concerns has significant drawbacks. Blockchain is not designed for data privacy. A ‘distributed' ledger will be used to store the data. Another issue is the immutability of blockchain. Data entered into the ledger cannot be changed or deleted. It will be impossible to remove personal data from the ledger even if desired.
MIT's Enigma Project aims to solve this. Enigma's ‘Secret Network' allows nodes to process data without seeing it. Decentralized applications can use Secret Network to use encrypted data without revealing it.
Another startup, Oasis Labs, uses blockchain to address data privacy issues. They are working on a system that will allow businesses to protect their customers' data.
Conclusion
Blockchain technology is already being used. Several governments use blockchain to eliminate centralized servers and improve data security. In this information age, it is vital to safeguard our data. How blockchain can help us in this matter is still unknown as the world explores the technology.

mbvissers.eth
3 years ago
Why does every smart contract seem to implement ERC165?
ERC165 (or EIP-165) is a standard utilized by various open-source smart contracts like Open Zeppelin or Aavegotchi.
What's it? You must implement? Why do we need it? I'll describe the standard and answer any queries.
What is ERC165
ERC165 detects and publishes smart contract interfaces. Meaning? It standardizes how interfaces are recognized, how to detect if they implement ERC165, and how a contract publishes the interfaces it implements. How does it work?
Why use ERC165? Sometimes it's useful to know which interfaces a contract implements, and which version.
Identifying interfaces
An interface function's selector. This verifies an ABI function. XORing all function selectors defines an interface in this standard. The following code demonstrates.
// SPDX-License-Identifier: UNLICENCED
pragma solidity >=0.8.0 <0.9.0;
interface Solidity101 {
function hello() external pure;
function world(int) external pure;
}
contract Selector {
function calculateSelector() public pure returns (bytes4) {
Solidity101 i;
return i.hello.selector ^ i.world.selector;
// Returns 0xc6be8b58
}
function getHelloSelector() public pure returns (bytes4) {
Solidity101 i;
return i.hello.selector;
// Returns 0x19ff1d21
}
function getWorldSelector() public pure returns (bytes4) {
Solidity101 i;
return i.world.selector;
// Returns 0xdf419679
}
}This code isn't necessary to understand function selectors and how an interface's selector can be determined from the functions it implements.
Run that sample in Remix to see how interface function modifications affect contract function output.
Contracts publish their implemented interfaces.
We can identify interfaces. Now we must disclose the interfaces we're implementing. First, import IERC165 like so.
pragma solidity ^0.4.20;
interface ERC165 {
/// @notice Query if a contract implements an interface
/// @param interfaceID The interface identifier, as specified in ERC-165
/// @dev Interface identification is specified in ERC-165.
/// @return `true` if the contract implements `interfaceID` and
/// `interfaceID` is not 0xffffffff, `false` otherwise
function supportsInterface(bytes4 interfaceID) external view returns (bool);
}We still need to build this interface in our smart contract. ERC721 from OpenZeppelin is a good example.
// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.5.0) (token/ERC721/ERC721.sol)
pragma solidity ^0.8.0;
import "./IERC721.sol";
import "./extensions/IERC721Metadata.sol";
import "../../utils/introspection/ERC165.sol";
// ...
contract ERC721 is Context, ERC165, IERC721, IERC721Metadata {
// ...
function supportsInterface(bytes4 interfaceId) public view virtual override(ERC165, IERC165) returns (bool) {
return
interfaceId == type(IERC721).interfaceId ||
interfaceId == type(IERC721Metadata).interfaceId ||
super.supportsInterface(interfaceId);
}
// ...
}I deleted unnecessary code. The smart contract imports ERC165, IERC721 and IERC721Metadata. The is keyword at smart contract declaration implements all three.
Kind (interface).
Note that type(interface).interfaceId returns the same as the interface selector.
We override supportsInterface in the smart contract to return a boolean that checks if interfaceId is the same as one of the implemented contracts.
Super.supportsInterface() calls ERC165 code. Checks if interfaceId is IERC165.
function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
return interfaceId == type(IERC165).interfaceId;
}So, if we run supportsInterface with an interfaceId, our contract function returns true if it's implemented and false otherwise. True for IERC721, IERC721Metadata, andIERC165.
Conclusion
I hope this post has helped you understand and use ERC165 and why it's employed.
Have a great day, thanks for reading!
