ERC223 SafeMath Functions

Question

  function max64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a >= b ? a : b;
  }

  function min64(uint64 a, uint64 b) internal constant returns (uint64) {
    return a < b ? a : b;
  }

  function max256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a >= b ? a : b;
  }

  function min256(uint256 a, uint256 b) internal constant returns (uint256) {
    return a < b ? a : b;
  }

What do these functions do? Source: https://github.com/Dexaran/ERC223-token-standard/blob/master/SafeMath.sol

Answer 1

? is commonly known as the ternary operator.

x ? y : z means roughly "if x then return y else return z".

So these functions do what they say they do. They return the maximum or minimum of their two arguments.