ABI Encoding-Decoding.md

77 - ABI Encoding-Decoding

ABI Encoding and Decoding Functions:

1. abi.decode(bytes memory encodedData, (...)) returns (...): ABI-decodes the given data, while the types are given in parentheses as second argument.

2. abi.encode(...) returns (bytes memory): ABI-encodes the given arguments

3. abi.encodePacked(...) returns (bytes memory): Performs packed encoding of the given arguments. Note that packed encoding can be ambiguous!

4. abi.encodeWithSelector(bytes4 selector, ...) returns (bytes memory): ABI-encodes the given arguments starting from the second and prepends the given four-byte selector

5. abi.encodeWithSignature(string memory signature, ...) returns (bytes memory): Equivalent to abi.encodeWithSelector(bytes4(keccak256(bytes(signature))), …)

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Slide Screenshot

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Slide Deck

• abi.encode(...)
• abi.decode(...)
• abi.encodeWithSelector(...)
• abi.decodeWithSignature(...)
• abi.encodePacked(...)
• Packed Encoding -> Ambiguous

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References

• Youtube Reference

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Code Examples

addr.call(abi.encodeWithSignature("transfer(address,uint256)", 0xSomeAddress, 123))

bytes4 selector = bytes4(keccak256("someFunc(address,uint256)"));
abi.encodeWithSelector(selector, _param1, _param2)