Bless Hukporti Depauli1

Answers to Deep Questions about Solidity

Question by /u/drcode

I won't talk about low-level opcodes here because of the brevity of the answer. In general, there are four ways functions can be called in Solidity:

	// SPDX-License-Identifier: MIT
	// ^ recommended, included machine readable in bytecode metadata
	// Software Package Data Exchange is an open standard

	pragma solidity ^0.8.7;
	// ^ floating pragma, min 0.8.7 max excluding 0.9.0
	// same as complex pragma: pragma solidity >=0.8.7 <0.9.0;
	// major.breakingchanges.bugfixes
	// only makes the compiler check for compatibility and throws error if not matching!
	// should only be floating during development, fixed everywhere during testing & deployment

	// SPDX-License-Identifier: MIT
	// ^ recommended, included machine readable in bytecode metadata
	// Software Package Data Exchange is an open standard

	pragma solidity ^0.8.7;
	// ^ floating pragma, min 0.8.7 max excluding 0.9.0
	// same as complex pragma: pragma solidity >=0.8.7 <0.9.0;
	// major.breakingchanges.bugfixes
	// only makes the compiler check for compatibility and throws error if not matching!
	// should only be floating during development, fixed everywhere during testing & deployment