Why PHP returns false in if condition when array_sum() value is 1?

Question

I am facing one weird issue, sum of array is 1 but when I checking it into the IF condition it returns false.

$array = array
(
    0 => 0.237,
    1 => 0.318,
    2 => 0.215,
    3 => 0.06,
    4 => 0.069,
    5 => 0.053,
    6 => 0.048
);

if(array_sum($array) != 1){
    echo "It's not one";
} else {
    echo "It's one"; 
}

Above code is returning It's not one instead of It's one.

How I need to resolve this issue? I have checked array_sum($arrays), It is showing 1. — Jimesh Gajera, Nov 30 '18 at 07:18
Depends on how accurate it needs to be. You could use `round()`, `ceil()`, `floor()` or `bcmath` extension (and more) depending on what your requirements are. — Jonnix, Nov 30 '18 at 07:22
I need to check sum of array values which must be 1 and my array is dynamic. — Jimesh Gajera, Nov 30 '18 at 07:27
`array_walk($array, function(&$i) { $i *= 100; }); if(array_sum($array) != 100) { …` — misorude, Nov 30 '18 at 07:43

score 1 · Answer 1 · answered Nov 30 '18 at 07:25

1

Try this solution

$sum=number_format(array_sum($array));
if($sum != 1){
    echo "It's not one";
} else {
    echo "It's one"; 
}

answered Nov 30 '18 at 07:25

josephthomaa

158
1
11

score 1 · Answer 2 · answered Nov 30 '18 at 07:27

1

You cannot compare float values without rounding them. See more here >> http://php.net/manual/en/language.types.float.php

You can do it as below,

$array = array
(
    0 => 0.237,
    1 => 0.318,
    2 => 0.215,
    3 => 0.06,
    4 => 0.069,
    5 => 0.053,
    6 => 0.048
);

if(round(array_sum($array)) != 1){
    echo "It's not one";
} else {
    echo "It's one"; 
}

answered Nov 30 '18 at 07:27

Nuwan Attanayake

1,161
9
20

Yes, But I need to check my values must be 1. So, I can't apply round on that. – Jimesh Gajera Nov 30 '18 at 07:31
in php, `floatval(1) == 1.0000000000000001`.So your sum value has to be rounded at least into 15 decimals – Nuwan Attanayake Nov 30 '18 at 07:34
1

in your case rounding into 3 decimal places would be the best solution `round(array_sum($array), 3)` – Nuwan Attanayake Nov 30 '18 at 07:38
It is working with if((float) trim(array_sum($array) != 1) – Jimesh Gajera Nov 30 '18 at 07:47
Great. only difference from rounding is you're doing it in 2 steps.First trim them cast.anyway this is working then cheers! – Nuwan Attanayake Nov 30 '18 at 07:50
Yes, Thank you for look into this. – Jimesh Gajera Nov 30 '18 at 07:51

Why PHP returns false in if condition when array_sum() value is 1?

2 Answers2