Detailed explanation of strtr string replacement usage in PHP, strtr string_PHP tutorial

Detailed explanation of strtr string replacement usage in PHP, strtr string

The example in this article describes the usage of strtr string replacement in PHP. Share it with everyone for your reference. The specific analysis is as follows:

strtr(string,from,to) or strtr(string,array)

First of all, for the first method of strtr function, let’s take a look at the following example. The code is as follows:

Copy code The code is as follows:

echo strtr("I Love you","Lo","lO");
?>

The result is:
1 I lOve yOu
This result reminds us that 1. strtr is case-sensitive, and 2. the replacement of strtr is very special. Please pay attention to the yOu at the back. The O in the middle is replaced. This is obviously not our intention. Here is another special An example to illustrate the weirdness of this php sttr function, the code is as follows:

Copy code The code is as follows:

echo strtr("I Love you","Love","");
?>

The result is:
I love you
Nothing will change, so what you need to pay attention to is that strtr cannot be replaced with nothing, that is, the last parameter cannot be an empty string. Of course, spaces are allowed. Here is another example of the strtr function. The code is as follows:

Copy code The code is as follows:

echo strtr("I Loves you","Love","lOvEA");
?>

The running result is
1 I lOvEs yOu
Note that A in the third parameter does not appear in the result.

I don’t recommend using strtr to exchange less for more. Since this strtr function is quite troublesome, why use it? The reason is that it is very fast. It is said that strtr is four times faster than str_replace, so you must use the strtr function when you can. How to use it comfortably? This is its second case: strtr(string,array)

Strtr is used as desired, the code is as follows:

Copy code The code is as follows:

$table_change = array('you'=>'her sister');
echo strtr("I Love you",$table_change);
?>

The result is:
I Love her sister
Tips: Just add whatever you want to replace to the array. For example, the code is as follows:

Copy code The code is as follows:

$table_change = array('you'=>'her sister');
$table_change += array('Love' => 'hate');
echo strtr("I Love you",$table_change);
?>

The result is
I hate her sister
Let me remind you again that writing Love as love will not work. I talked about it in a mess. In fact, what I want to say most about strtr is that the usage at the end is simple and convenient. It seems that the usage at the end also ignores the problem of different character lengths before and after. The above php strtr Function experiment, PHP5.2 test passed, the code is as follows:

Copy code The code is as follows:

//The output at this time is baicai instead of bai123cai, because str("pao") echo strtr("paocai!","pao","bai123");
?>

Example 2: When the length of the replaced value is less than the replaced target, the following is the quoted content, and the code is as follows:

Copy code The code is as follows:

//The output at this time is laocai instead of lacai, because str("pao")>strlen("la")
echo strtr("paocai!","pao","la");
?>

Example 3: Supports array replacement, the following is the quoted content, the code is as follows:

Copy code The code is as follows:

$Arr=array('ao'=>'oa','ai'=>'ia');
echo strtr("paocai!",$Arr); //The output at this time is poacia
?>

Next is str_replace, the following is the quoted content, the code is as follows:

Copy code The code is as follows:

echo str_replace("you","paocai","I love you!"); //I love paocai!
will be output ?>

I hope this article will be helpful to everyone’s PHP programming design.

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