CODEWITHSUNDEEP
phpdifference
Heap drip
Heap drip

Reputation: 41

compare two and find the difference between two string using php

I have a code to show difference between two sentences. But i need to check without case sensitive. 

<?php

function get_decorated_diff($old, $new){
    $from_start = strspn($old ^ $new, "\0");        
    $from_end = strspn(strrev($old) ^ strrev($new), "\0");

    $old_end = strlen($old) - $from_end;
    $new_end = strlen($new) - $from_end;

    $start = substr($new, 0, $from_start);
    $end = substr($new, $new_end);
    $new_diff = substr($new, $from_start, $new_end - $from_start);  
    $old_diff = substr($old, $from_start, $old_end - $from_start);

    $new = "$start<ins style='background-color:#ccffcc'>$new_diff</ins>$end";
    $old = "$start<del style='background-color:#ffcccc'>$old_diff</del>$end";
    return array("old"=>$old, "new"=>$new);
}


$string_old = "Hello World!";
$string_new = "hello world!";
$diff = get_decorated_diff($string_old, $string_new);
echo "<table>
    <tr>
        <td>".$diff['old']."</td>
        <td>".$diff['new']."</td>
    </tr>
</table>";
?>

It shows diffrence for Hello and hello . But i need to show difference without case sensitive

Upvotes: 1

Views: 5437

Answers (4)

ScaisEdge
ScaisEdge

Reputation: 133400

you could set to lowercase at the begin of the function 

 function get_decorated_diff($old, $new){
    $old = strlower($old);
    $new = strlower($new);

    $from_start = strspn($old ^ $new, "\0");   
     .......

if you need to preserve the originale values you can make a copy for return later the original content

Upvotes: 1

MisterX
MisterX

Reputation: 310

Try to make all strings in one case, as example

function get_decorated_diff($old, $new){
    $originalOld = $old;
    $originalNew = $new;
    $old = strtolower($old); //Add this line
    $new = strtolower($new); //Add this line

    $from_start = strspn($old ^ $new, "\0");        
    $from_end = strspn(strrev($old) ^ strrev($new), "\0");

    $old_end = strlen($old) - $from_end;
    $new_end = strlen($new) - $from_end;

    $start = substr($new, 0, $from_start);
    $end = substr($new, $new_end);
    $new_diff = substr($originalNew, $from_start, $new_end - $from_start);  
    $old_diff = substr($originalOld, $from_start, $old_end - $from_start);

    $new = "$start<ins style='background-color:#ccffcc'>$new_diff</ins>$end";
    $old = "$start<del style='background-color:#ffcccc'>$old_diff</del>$end";
    return array("old"=>$old, "new"=>$new);
}

Upvotes: 1

Adder
Adder

Reputation: 5878

Since ('a' ^ 'A') = ' ' i.e. space character, you can use this code to compare regardless of case:

$from_start = strspn($old ^ $new, "\0 ");        
$from_end = strspn(strrev($old) ^ strrev($new), "\0 ");

However, it will also have false matches when the characters to compare are not letters.

Upvotes: 0

Mohideen bin Mohammed
Mohideen bin Mohammed

Reputation: 20206

made it lowercase and do comparison 

$old_lower = strlower($old);
$new_lower = strlower($new);
$from_start = strspn($old_lower ^ $new_lower, "\0");

To compare strings with case-insensitively, use strcasecmp:

<?php
$string_old = "Hello World!";
$string_new = "hello world!";
if (strcasecmp($string_old, $string_new) == 0) {
    echo '$string_old is equal to $string_new in a case-insensitive string comparison';
}
else {
    echo = 'there is difference between $string_old with $string_new';
}
?>

Upvotes: 0

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