How can i detect if (float)0 == 0 or null in PHP

Question

If variable value is 0 (float) it will pass all these tests:

    $test = round(0, 2); //$test=(float)0

    if($test == null)
        echo "var is null";
    if($test == 0)
        echo "var is 0";
    if($test == false)
        echo "var is false";
    if($test==false && $test == 0 && $test==null)
        echo "var is mixture";

I assumed that it will pass only if($test == 0)

Only solution I found is detect if $test is number using function is_number(), but can I detect if float variable equal zero?

Use `===` instead of `==`. That way you can compare data types as well — John Conde, Jul 30 '14 at 13:36
http://3v4l.org/usPbP - Test againsts 0.0 or use is_float to check if it's a float or not first. Obviously `=== 0.0` is as fast as you're going to see. — scragar, Jul 30 '14 at 13:39
If you test against zero imho this works the best: if( round( $test, 1) === 0.0 ) { ... } — gramgram, Sep 08 '20 at 12:35

Markus Kottländer · Accepted Answer · 2014-07-30T14:00:03.287

24

Using === checks also for the datatype:

$test = round(0, 2); // float(0.00)

if($test === null) // false
if($test === 0) // false
if($test === 0.0) // true
if($test === false) // false

edited Jul 30 '14 at 14:00

answered Jul 30 '14 at 13:39

Markus Kottländer

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`0 == 0.0 && 0 !== 0.0` Floats and ints are non-comparable with triple equals. – scragar Jul 30 '14 at 13:40
Had trouble checking whether my float variable's value was 0 or null! This helped thanks! – Mehravish Temkar Dec 19 '16 at 07:25

score 2 · Answer 2 · answered Jul 30 '14 at 13:37

2

Use 3 equal signs rather than two to test the type as well:

if($test === 0)

answered Jul 30 '14 at 13:37

ksealey

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score 0 · Answer 3 · edited Jul 31 '14 at 09:38

If you use=== instead of == it will compare as well as get the data types errors manage...Can you post your answer while using === ? Please check the difference between this two here

When comparing values in PHP for equality you can use either the == operator or the === operator. What’s the difference between the 2? Well, it’s quite simple. The == operator just checks to see if the left and right values are equal. But, the === operator (note the extra “=”) actually checks to see if the left and right values are equal, and also checks to see if they are of the same variable type (like whether they are both booleans, ints, etc.).

How can i detect if (float)0 == 0 or null in PHP

3 Answers3