Chaining Assignation¶
Chaining assignation is the ability to assign the same value to several variables in a single expression, using successive = operators.
The assignment is evaluated from right to left: the rightmost value is assigned first, then the result propagates leftward. Each = operator returns the assigned value, which becomes the operand of the next assignment.
Note that magic methods such as __set() and __get() are never called during chaining assignments. Writing $a = $obj->b = 8; will not trigger __set() on $obj.
<?php
// Basic chaining assignation
$a = $b = $c = 0;
// $a, $b, $c are all 0
// Right-to-left evaluation
$x = ($y = 5) + 3;
// $y is 5, $x is 8
// Chaining with a function call
$arr = $count = count([1, 2, 3]);
// both $arr and $count are 3
?>
See also Assignment Operators and Operator Precedence.
Related : , __set() Method, __get() Method, Chaining (disambiguation), Chaining New Without Parenthesis
