- <?php
- /**
- *
- * @param String $string
- * @return float
- *
- * Returns a float between 0 and 100. The closer the number is to 100 the
- * the stronger password is; further from 100 the weaker the password is.
- */
- function password_strength($string){
- $h = 0;
- $size = strlen($string);
- foreach(count_chars($string, 1) as $v){
- $p = $v / $size;
- $h -= $p * log($p) / log(2);
- }
- $strength = ($h / 4) * 100;
- if($strength > 100){
- $strength = 100;
- }
- return $strength;
- }
- var_dump(password_strength("Correct Horse Battery Staple"));
- echo "<br>";
- var_dump(password_strength("Super Monkey Ball"));
- echo "<br>";
- var_dump(password_strength("Tr0ub4dor&3"));
- echo "<br>";
- var_dump(password_strength("abc123"));
- echo "<br>";
- var_dump(password_strength("sweet"));
来源: http://www.phpxs.com/code/1003459/