PHP interception string function strtr/str_replace

/**

* 1. strtr converts the specified characters

*

* string strtr ( string $str , string $from , string $to )

* string strtr ( string $str , array $replace_pairs )

*

* This function returns a copy of str and converts the characters specified in from to the corresponding characters in to.

* If from and to are not equal in length, the extra characters will be ignored.

*/

$str = 'http://flyer0126.iteye.com/';

echo strtr($str, 'IT', 'java');

//output: http://flyer0126.iteye.com/ strtr is case sensitive

//If from and to are not equal in length, the extra characters will be ignored

echo strtr($str , 'it', 'java');

//output： haap://flyer0126.jaeye.com/

//iteye --> jaeye it is only replaced by ja

//http --> ; haap replaces corresponding positions character by character, which does not meet our original intention

echo strtr($str, 'it', '');

//output: http://flyer0126.iteye.com / No replacement

echo strtr($str, 'it', ' ');

//output: http://flyer0126.teye.com/ Can be replaced

/**

* A summary of the from->to method of function strtr:

* 1. Case sensitive;

* 2. When the lengths of form and to are not equal, the extra characters will be ignored, and you cannot replace less with more, or Cannot replace more with less;

* 3. Replace corresponding positions character by character;

* 4. Cannot be replaced with empty space, but can be replaced with spaces.

*/

// In comparison, the latter method is obviously more appropriate

$replace_pairs = array(

'http://'=>'',

'it' = > 'java'

);

echo strtr($str, $replace_pairs);

//output: flyer0126.javaeye.com/ The replacement was successful and in line with the original intention of the replacement

/**

 * 2. 函数 str_replace

 * mixed str_replace ( mixed $search , mixed $replace , mixed $subject [, int &$count ] )

  */

echo str_replace('it', 'java', $str);

//output: http://flyer0126.javaeye.com/

echo str_replace(array('http', ' :', '//', '/'), '', $str);

//output: flyer0126.iteye.com

echo str_replace(array('http', 'it', '/') , array('https', 'java', ''), $str);

//output: https:flyer0126.javaeye.com