Finding string inside variable

Question

I'm trying to find a string inside a variable. The problem is that it doesn't look for a unique string.
For example, a have a variable with the following values:

$mystring = "p,pp,m,g";

Here's the code that I'm using:

<?php 
    $find="pp";
    if(strstr($mystring, $find)==true){
        echo "found"; 
    } 
?>

The problem is: when I'm looking for pp, it also returns "p" as a result. How can I avoid this kind of error?
I'm using it to check the sizes of a item on an ecommerce website and I'm struggling to get it right.

Any ideas?!

I tried you code. It is working fine for me. It echo found if pp is found. If i remove pp from $mystring, it does not echo anything!!! — William Buttlicker
– William Buttlicker, Commented Feb 6, 2013 at 12:41

Zevi Sternlicht · Accepted Answer · 2013-02-06 12:42:40Z

2

Use strpos. Make sure you use the !== operator.

echo strpos($mystring, $find) !== false ? 'found' : 'not found';

answered Feb 6, 2013 at 12:42

Zevi Sternlicht

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2 Comments

Zevi Sternlicht Over a year ago

@user1541940 then you need to use preg_match() and specify that you want no p next to it

fackz Over a year ago

right, it's harder than I thought...I'm thinking in just changing the sizes from letters to numbers...thanks anyway!

Prasanth Bendra · Accepted Answer · 2013-02-07 04:26:53Z

1

$mystring = "p,pp,m,g";
$str      = explode(",",$mystring);

$find     = "/^pp$/";
foreach($str as $val){
   if(preg_match($find, $val)){
       echo "found => ".$val; 
   }else{
       echo "not found";
   }
}

ref: http://php.net/manual/en/function.preg-match.php

edited Feb 7, 2013 at 4:26

answered Feb 6, 2013 at 12:54

Prasanth Bendra

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4 Comments

fackz Over a year ago

Same problem here...it works but it returns true for p or pp because "pp" also has a "p"...got it?!

Prasanth Bendra Over a year ago

each , separated need to match ? OR it is a single string ?

fackz Over a year ago

each, separated need to match.

Prasanth Bendra Over a year ago

Edited the code please check it. Please note the ^ and $ in find string. ref: php.net/manual/en/function.preg-match.php

Andrei · Accepted Answer · 2013-02-06 12:51:27Z

0

You can use transformating to array and search as array's element:

$mystring = "p,pp,m,g";
$arr = explode(',',$mystring);
if (in_array('p',$arr,true)) {echo "found";}

Or (http://php.net/manual/en/function.strstr.php: "If you only want to determine if a particular needle occurs within haystack, use the faster and less memory intensive function strpos() instead") you can write

if (strpos($mystring,'pp')!==false) {echo 'found';} else {echo 'not found';}

edited Feb 6, 2013 at 12:51

answered Feb 6, 2013 at 12:45

Andrei

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Comments

fackz · Accepted Answer · 2013-02-06 19:35:52Z

0

Just changed the values and used the same strstr function to avoid similar letters problem.

answered Feb 6, 2013 at 19:35

fackz

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