checking zero is null or not in php

Question

i am working on validation and comparisons!! i have a field that can contain the value $val=0 or $val="some-value" or $val="" or $val=0 basically i want the $val="0"or $val=0 to be validated as true..

 if($val){
    //works for $val="some-value"
//doesnot work for $val=0 or $val="0";
    } else
    {
    //works corrent for $val=""
    }

one conditional approach i used is

$val="";

    if($val || $val==0){
    echo "true";
}
else
{
//should be false but it is true
    echo "false";
}

basically i want the $val="0"or $val=0 and $val="" to be validated as true.. — uneeb, Nov 29 '16 at 15:24
`$val="" to be validated as true.`, `only $val=""; should not be validated` Which is true? — u_mulder, Nov 29 '16 at 15:26
Possible duplicate of [The 3 different equals](http://stackoverflow.com/questions/2063480/the-3-different-equals) — u_mulder, Nov 29 '16 at 15:29

Vincent Dapiton · Accepted Answer · 2016-11-29T15:35:47.923

1

did you try this?

$val = "";

if ($val == '0') {
    echo "TRUE";
        # code...
    }   
elseif ($val == "") {
        echo "FALSE";
    }

edited Nov 29 '16 at 15:35

answered Nov 29 '16 at 15:30

Vincent Dapiton

587
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o thanks man! i was using php functions as i got confused between string and integer comparisons that was so simple thanks...:) – uneeb Nov 29 '16 at 15:36

Oleks · Answer 2 · 2016-11-29T15:30:53.350

0

There is a useful php native function is_null

if (is_null($val) || $val === "") {
    //invalid
} else {
   //valid
}

edited Nov 29 '16 at 15:30

answered Nov 29 '16 at 15:25

Oleks

1,633
1
18
22

almost there but it is validating $val=""; as true which i want false – uneeb Nov 29 '16 at 15:27
much appreciated...:) – uneeb Nov 29 '16 at 15:38

Saumya Rastogi · Answer 3 · 2016-11-29T15:32:10.870

0

You can use PHP integer casting & can do it like this:

if ((int) $val === 0) {
  return true;
} else {
  return false;
}

Hope this helps!

edited Nov 29 '16 at 15:32

answered Nov 29 '16 at 15:31

Saumya Rastogi

13,159
5
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`return empty($val)` – u_mulder Nov 29 '16 at 15:31
much appreciated..:) – uneeb Nov 29 '16 at 15:36
@uneeb - If you find this answer correct and helpful then accept or upvote this answer as it motivates me to give answers to other questions like this and helps others to quickly find the correct answer! – Saumya Rastogi Nov 29 '16 at 15:39

checking zero is null or not in php

3 Answers3