comparing float 0 to 0 - php

Question

In the following code, I expect the if condition to be true, but actually the else condition is true. Can anyone explain the reason behind it?

$a = (float) 0;
$b = 0;
if ($b === $a) {
    echo "$a and $b are equal";
}
else{
    echo "$a and $b are not equal";  // true
}

use `==` - it matches values not based on type, `===` matches value and type — treyBake, Apr 13 '18 at 15:43
You're echoing the same string in both conditions. How do you know which part is being triggered if they're both the same? — Ibrahim Hafiji, Apr 13 '18 at 15:45
*in the following code, I expect "if" condition to be true* - why? If you know what triple equals does in PHP, then you shouldn't ever expect it to return true for different data types. — iainn, Apr 13 '18 at 15:48

score 0 · Answer 1 · answered Apr 13 '18 at 15:44

0

=== checks if the value (0 & 0) and type (int & float) are equal. In this case they are not.

If you want to only check the value and not the type then use ==

answered Apr 13 '18 at 15:44

Bram

19
5

Thanks for the answer :) – nik Apr 13 '18 at 15:49

Always Sunny · Accepted Answer · 2018-04-13T15:56:46.597

0

The else part is true because int(0) and float(0) is not equal when you try with ===, the if part will be true if you try with ==. See their datatype with var_dump($a) or var_dump($b)

=== not only compares value are equal but also ensures that entries are of same type

<?php
$a = (float) 0;
$b = 0;
var_dump($a);
var_dump($b);
if($b === $a){
    echo "$a and $b are equal";
}else{
    echo "$a and $b are not equal";  // true
}
?>

edited Apr 13 '18 at 15:56

answered Apr 13 '18 at 15:46

Always Sunny

32,751
7
52
86

did you know that the var_dump function is variadic? – hanshenrik Apr 13 '18 at 15:47
thanks, now i have understood, – nik Apr 13 '18 at 15:48
@nik best of luck. Happy coding. :) – Always Sunny Apr 13 '18 at 15:54

comparing float 0 to 0 - php

2 Answers2