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Questions tagged [erc-20]

The ERC20 Token Standard is a set of 8 functions to be included (in an agreed upon language) in a smart token contract in order to enable interoperability across multiple interfaces and dapps. These functions relate to (1) how tokens can be transferred (2) how to access data about the token, and (3) how to format key events like transfers and approvals. ERC stands for Ethereum Request for Comments.

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What are the practical uses of Allowance in ERC20 tokens?

I'm studying ERC20 specification and all seems to make sense. Well, all but allowance. I couldn't grasp to the concept and it's usefulness. What should I use it for? (Should I at all?) What are the drawbacks of setting an allowance for too high or…
sigmaxf
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Where is the ERC 20 token code?

I've read about and understand the idea behind the ERC20 Token Standard, but is there an official contract people can download and use? Or is it an official list of functions a smart contract should include in order to be up to standard? Anyone…
velua
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How to Receive ERC20 In smart Contract

Hello I'm pretty new to ERC20 and i try to research something but maybe concept in my head is not correct. I'm trying to create smart contract that is receiving some amount of ERC20, validating the input amount and if it's ok it continue with logic…
Andon Mitev
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What's the reason ERC-20 standard allows 0 value transfer?

ERC-20 says transfer and transferFrom should allow 0-value transfer and fire Transfer event. What's the main benefit of allowing 0-value transfer? Is there any use case?
conr2d
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Can i freeze portion of ERC20 tokens via smart-contract?

The Freezing functionality is to impose the restrictions on sales of some portion of ERC20 tokens for certain time periods in Admin Dashboard when transferring the ERC20 tokens to buyers. The Admin can randomly specify the freezing portion and…
Dhara Patel
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What is the first ever ERC20 token creation transaction?

Do you know the first ERC20 issuance transaction?
zono
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Is there an API that can find all the ERC20 token icons?

I'm trying to find icons for all ERC20 tokens, does any API provide that information ?.
Sunny
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How to Convert ERC-20 tokens back to Ether[eum]

From my understanding, Ether is converted to an ERC-20 token (like BAT), via a smart contract. Ether is assigned to that contract by sending Ether to the smart contract's address. Please correct me if I'm wrong in any of that. My question though is,…
user70192
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How can I get token info by the contract address?

0x5a65585ce8213d1c9433e63d53d4e468540a5019 is my CRC20 token. I can search the token info on etherscan. https://ropsten.etherscan.io/token-search Token Attributes Found: totalSupply = 100 name = ZONO symbol = ZONO decimals = 0 How can I do it…
zono
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What is the difference between transfer() and trasnferfrom() and when should i use it

I want to ask what is the difference between transfer and transferfrom AND WHEN should i use them in the following examples: 1- My friend wants to give tokens to other friends. What function is he going to call to send it to another and why (and…
super gmaer
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Wallet for ERC-20 Tokens

I'm working to understand ERC-20 tokens. I believe that I'm confused on a detail based on a previous SO question. Please allow me to use the Basic Attention Token (BAT) as an example. I have a Ledger Nano. On that Ledger Nano, I have $1.00 worth of…
Some User
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Is there a certification process or agency for ERC-20 tokens?

The EMV site claims that their token contracts are officialy ERC-20 certified and is listed here (then they give their EtherScan address). My question is whether there is a certification agency or process. I realize ERC-20 is a standard that can…
NealWalters
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Paying gas from different Address and sending from different

I am use Web3J 4.5.7 with Java 1.8 I am integrating ERC20 tokens for an exchange. We have a scenario. A user doesn't have any ETH in his address, but has ERC20 token, let's say USDT. Now the user wants to withdraw his USDT to some other wallet. But…
Gladiator9120
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Is there a way to create an ERC20 token with an unlimited supply?

When you initially create an ERC20 token, you must declare totalSupply. Is that the hard cap on the number of tokens you can create or is totalSupply rather just the initial token supply?
technoplato
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EtherScan API get erc20 token balance at specific block?

I am trying to find a way to get the balance of erc20 token of any specific address at given block. So far i succeeded in getting current balance but couldn't find a way to get it from the specific block using EtherScan API, is there a way? I am…
erc20Newbie
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