Search if a string exists in another string

Question

for my purposes I did this:

<?php
$mystring = 'Gazole,';
$findme   = 'Sans Plomb 95';
$pos = strpos($mystring, $findme);

if ($pos >= 0) {
    echo "The string '$findme' was found in the string '$mystring'";
    echo " and exists at position $pos";
} else {
    echo "The string '$findme' was not found in the string '$mystring'";
}
?>

However, it always executes this branch:

echo "The string '$findme' was found in the string '$mystring'";
echo " and exists at position $pos";

although the string I 'm searching for doesn't exist.

Please help, thx in advance :))

Jon · Accepted Answer · 2011-04-25 10:49:22Z

14

The correct way to do it is:

if ($pos !== false) {
    echo "The string '$findme' was found in the string '$mystring'";
    echo " and exists at position $pos";
} else {
    echo "The string '$findme' was not found in the string '$mystring'";
}

See the giant red warning in the documentation.

answered Apr 25, 2011 at 10:49

Jon

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Comments

Blagovest Buyukliev · Accepted Answer · 2011-04-25 10:55:47Z

3

strpos returns a boolean false in case the string was not found. Your test should be $pos !== false rather than $pos >= 0.

Note that the standard comparison operators do not consider the type of the operands, so that false is coerced to 0. The === and !== operators yield true only if the types and the values of the operands match.

edited Apr 25, 2011 at 10:55

answered Apr 25, 2011 at 10:49

Blagovest Buyukliev

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Comments

cweinberger · Accepted Answer · 2011-04-25 10:49:44Z

1

See the warning on the manual page

You need also to check if $pos !== false

answered Apr 25, 2011 at 10:49

cweinberger

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Comments

Ale · Accepted Answer · 2011-04-25 10:51:26Z

1

strpos() returns FALSE if the string was not found. When you check for $pos >= 0, you're accpeting that FALSE value.

Try this:

<?php
$mystring = 'Gazole,';
$findme   = 'Sans Plomb 95';
$pos = strpos($mystring, $findme);


if ($pos !== false) {
    echo "The string '$findme' was found in the string '$mystring'";
    echo " and exists at position $pos";
} else {
       echo "The string '$findme' was not found in the string '$mystring'";

}
?>

answered Apr 25, 2011 at 10:51

Ale

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Comments

Dinash · Accepted Answer · 2011-04-25 10:52:38Z

1

hi malek strpos method in php will return a boolean of value false when the string is not found and if found it will return the position in int.

refer this Link to study about strpos

answered Apr 25, 2011 at 10:52

Dinash

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Comments

Hoàng Vũ Tgtt · Accepted Answer · 2014-04-16 17:39:18Z

0

if (strpos($mystring, $findme) !== false) {
    echo 'true';
}

answered Apr 16, 2014 at 17:39

Hoàng Vũ Tgtt

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Enigma Plus · Accepted Answer · 2018-12-13 18:33:32Z

0

Completely different way to do it without worrying about indexes:

if (str_replace($strToSearchFor, '', $strToSearchIn) <> $strToSearchIn) {
    //strToSearchFor is found inside strToSearchIn

What you are doing is replacing out any occurrence of the substring and checking if the result is the same as the original string.

answered Dec 13, 2018 at 18:33

Enigma Plus

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