Ignore case sensitivity when comparing strings in PHP

Question

I'm trying to compare words for equality, and the case [upper and lower] is irrelevant. However PHP does not seem to agree! Any ideas as to how to force PHP to ignore the case of words while comparing them?

$arr_query_words = ["hat","Cat","sAt","maT"]; for( $j= 0; $j < count($arr_query_words); $j++ ){     $story_body = str_replace(          $arr_query_words[ $j ],         '<span style=" background-color:yellow; ">' . $arr_query_words[ $j ] . '</span>',         $story_body    ); } 

Is there a way to carry out the replace even if the case is different?

Answer 1

Use str_ireplace to perform a case-insensitive string replacement (str_ireplace is available from PHP 5):

$story_body = str_ireplace($arr_query_words[$j],    '<span style=" background-color:yellow; ">'. $arr_query_words[$j]. '</span>',     $story_body); 

To case-insensitively compare strings, use strcasecmp:

<?php $var1 = "Hello"; $var2 = "hello"; if (strcasecmp($var1, $var2) == 0) {     echo '$var1 is equal to $var2 in a case-insensitive string comparison'; } ?> 

Answer 2

The easiest, and most widely supported way to achieve this is possibly to lowercase both strings before comparing them, like so:

if(strtolower($var1) == strtolower($var2)) {     // Equals, case ignored } 

You might want to trim the strings being compared, simply use something like this to achieve this functionality:

if(strtolower(trim($var1)) == strtolower(trim($var2))) {     // Equals, case ignored and values trimmed }