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phpcomparisonequals-operator

Are all PHP equality comparisons symmetric?

Is $a == $b always equivalent to $b == $a?

I think in JavaScript there are a few weird cases where that's not true, due to casting.

I think ide is correct. I'll ask another question.

Solution

  • Depends what happens between those two calls. Otherwise yes, those are the same. The order makes no difference. Using 2 equals == A string of 1 and integer of 1, will return true when compared. Type is ignored, only value is compared. So no wierdness.

    http://php.net/manual/en/language.operators.comparison.php

    <?

$a=(string) 1;
$b=(int) 1;

var_dump($a);
var_dump($b);


echo $a==$b;

    Outputs: 1

    http://www.ideone.com/JLJWQ

    EDIT

    To clarify, there is absolutely nothing you can ever put in $a or $b to get a different output on the comparison, just by putting it on the other side of the operator.

    $a="1234";
$b="1234";

echo $a==$b;
echo $b==$a;

    The output of that, for any $a or $b values, will always without a doubt be true true, or false false.