<p>It's a <strong>standard</strong>.</p>

<p>ALL those ERC20 based tokens have (at least) the same attribute names, the same method names.</p>

<p>So I do automaticly know that I need to call the method "transfer" when I want to transfer my tokens. No one would name it "transfer_tokens_hello_world". Irrelevant which of the thousands of token I want to transfer: It's always the same method.</p>

<p>The advantage for exchanges and/or user interfaces is that it's really easy to implement. If an exchange list token A and B, then token C has the same structure and it's easy to implement it, too.</p>

CC BY-SA 3.0
2018-03-24T20:13:23.097Z
Thanks. In case exchange tokens, I have 2 points that I don't understand: 1. Who decide transfer rate between 2 different tokens. 2. Why does ERC20 support exchange token ? thanks.
hqt
CC BY-SA 3.0
2018-03-24T19:37:07.663Z
2018-03-24T19:37:07.663Z
hardfork
<p>I am studying to write smart contract and see that there are some token standards such as <a href="https://theethereum.wiki/w/index.php/ERC20_Token_Standard" rel="nofollow noreferrer">ERC20</a>. My question is: what is the purpose of those standards ? Why do we need to add those interface to our code rather than just implement "some" functions that we need.</p>

<p>Thanks</p>

<smartcontracts>
Purpose of token standard interfaces when implement smart contract
hqt
# Purpose of token standard interfaces when implement smart contract

(Asked by: username_0 on 2018-03-24)

I am studying to write smart contract and see that there are some token standards such as [ERC20](https://theethereum.wiki/w/index.php/ERC20_Token_Standard). My question is: what is the purpose of those standards ? Why do we need to add those interface to our code rather than just implement "some" functions that we need.

Thanks

**Tags:** smartcontracts


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## 1 answers

### Answer by username_1 on 2018-03-24. Score: 3

It's a **standard**.

ALL those ERC20 based tokens have (at least) the same attribute names, the same method names.

So I do automaticly know that I need to call the method "transfer" when I want to transfer my tokens. No one would name it "transfer\_tokens\_hello\_world". Irrelevant which of the thousands of token I want to transfer: It's always the same method.

The advantage for exchanges and/or user interfaces is that it's really easy to implement. If an exchange list token A and B, then token C has the same structure and it's easy to implement it, too.

> **Comments:**
> **username_0**: Thanks. In case exchange tokens, I have 2 points that I don't understand: 1. Who decide transfer rate between 2 different tokens. 2. Why does ERC20 support exchange token ? thanks.  

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