如何检查字符串是否在Php中包含确切的子字符串

Question

I am trying to check if a number say 1 is present in a string say 11,12,13 To do this I am using strpos :

<?
$s = "2,3,11,12,13";
$ss = "1";
if(strpos($s, $ss)) echo "success";
else echo "fail";
?>

Here I am expecting the code to give fail as output but it gives success . Is there any function I can use to exactly match the number in a string. I want the number 1 in the string, not the numbers containing 1 like 11,123,100 etc.

Edit 1: It works fine for @Twinfriends answer but the problem is doing it with multiple numbers.

<?
    $s = "2,3,11,12,13";
    $ss = "1,2";
    if(strpos($s, $ss)) echo "success";
    else echo "fail";
    ?>

This code gives output fail but it should give true.

Edit 2: Check answer https://stackoverflow.com/a/48297002/8490014

The problem has been solved but because of for each loop the output is getting repeated as many times as there are values in the array. How can we get the output repeating the output?

Answer 1

You could do it like this:

<?php

$s = "2,3,11,12,13";
$ss = "1";

$toTest = explode(",", $s);

if(in_array("$ss", $toTest)) {
    echo "success";
}
else {
    echo "fail";
}

?>

If you've any question considering this code, feel free to ask. (Code tested, works well)

Answer 2

The problem has been solved by adding a foreach loop:

<?
$s = "2,3,11,12,13";
$ss = "1,2,3,5";

$catid = explode(",", $s);
$ocat = explode(",",$ss);

    foreach($ocat as $abc) {
if(in_array($abc, $catid)) {
 echo "success";
}
else {
echo "fail";
}
}
?>

Answer 3

Try this:

<?php
$s = "2,3,11,12,13";
$ss = "1";

$haystack = explode(",",$s);
$matches  = preg_grep ("/$ss/", $haystack);

echo !empty($matches) ? "success" : "fail";

Answer 4

You can check by appending comma after the variable to check occurrence at start , appending comma before the variable to check occurrence at last or appending comma before and after the variable to check occurrence at middle .

if((substr($s, 0, (strlen($ss)+1)) === $ss.',')||(substr($s, (strlen($s)-strlen($ss)-1), strlen($s)) === ','.$ss)||(strpos($s, ','.$ss.','))){
        echo "success";
}
else{
        echo "fail";
}