Tutorial by Examples

Generic example in a form of $a <=> $b matrix. 0 <=> 1; // -1 (left operand less than right, right is greater) 0 <=> 0; // 0 (operands are equal) 1 <=> 0; // 1 (left operand greater than right, left is greater) 1 <=> 1; // 0 (operands are equal) ╔═══════╦════╦═...

$array = [1, 0, 5, 9, 3, 7, 6, 8, 4, 2]; usort($array, function (int $a, int $b): int { return $a <=> $b; }); print_r($array); Array ( [0] => 0 [1] => 1 [2] => 2 [3] => 3 [4] => 4 [5] => 5 [6] => 6 [7] => 7 [8...

$a = 5; $b = 10; $a <=> $a; // 0, because $a == $a $a <=> $b; // -1, because $a < $b $b <=> $a; // 1, because $b > $a