Expressions And Operators: Ones Complement

The ones-complement operator, ~, performs a bitwise complement on its int operand and produces an int result. (That is, each bit in the result is set if and only if the corresponding bit in the operand is clear.) For example:

$lLetter = 0x73;              // lowercase letter 's'
$uLetter = $lLetter & ~0x20;  // clear the 6th bit to make uppercase letter 'S'