PHP: similar_text() function


The similar_text() function is used to calculate the number of similar characters between two strings.
The similar_text() function can also calculate the similarity of the strings in percent.


(PHP 4 and above)


similar_text(first_string, second_string, npercent) 


Name Description Required /
first_string The first input string. Required String
second_string The second input string. Required String
npercent Variable to store the percentage of similarity between the input strings. Optional Integer

Return value:

Returns the number of matching chars in both strings.

Value Type: Integer


echo "Comparing strings : 'Good Morning' and 'Good Evening'".'<br>';
echo 'No of similar characters : '.similar_text('Good Morning', 'Good Evening').'<br>';
similar_text('Good Morning', 'Good Evening', $similar_percent);
echo 'Similarity between two strings in  percentage : '. $similar_percent;


Comparing strings: 'Good Morning' and 'Good Evening'
No of similar   characters : 9
Similarity between two strings in  percentage : 75

View the example in the browser

See also

PHP Function Reference

Previous: sha1
Next: sprintf

PHP: Tips of the Day

In PHP, there are two versions of logical AND and OR operators.

Operator True if
$a and $b Both $a and $b are true
$a && $b Both $a and $b are true
$a or $b Either $a or $b is true
$a || $b Either $a or $b is true

Note that the && and || opererators have higher precedence than and and or. See table below:

Evaluation Result of $e Evaluated as
$e = false || true True $e = (false || true)
$e = false or true False ($e = false) or true

Because of this it's safer to use && and || instead of and and or.