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24 lines
940 B
Markdown
24 lines
940 B
Markdown
## ABI encoding
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* the solidity built-in function `abi.encode` encodes solidity types into raw bytes, that can be interpreted directly by the EVM.
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```
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contract StringEncoding {
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bytes public encodedString = abi.encode("hacking");
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}
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```
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* this is what happens:
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1. 1st (32 bytes) word = offset → indicates at which bytes index the string starts. If you count 32 from the beginning (= index 32), you will reach the starting point of where the actual encoded string starts.
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2. 2nd (32 bytes) word = string length → in the case of the string, this indicates how many characters (including whitespaces) are included in the string.
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3. 3rd (32 bytes) word = the actual utf8 encoded string → each individual bytes corresponds to hex notation of a letter / character encoded in utf8.
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<br>
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#### other ABI Encodings
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* address payable -> address
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* contract -> address
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* enum -> uint8
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* struct -> tuple of elementry types
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