Introduction to related methods of PHP string replacement_PHP tutorial

In actual programming, when we want to implement string replacement, we usually use the strtr() function. Now let’s explain in detail how to implement string replacement in PHP.

v Let’s first take a look at the two states of this PHP string replacement function strtr()

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

First of all, for the first method of strtr function
Let’s look at the following PHP string replacement example:

<ol class="dp-xml"><li class="alt"><span><span class="tag">< ?</span><span class="tag-name">php</span><span> </span></span></li><li><span>echo strtr("I Love you<br />","Lo","lO");  </span></li><li class="alt"><span class="tag">?></span><span>   </span></span></li></ol>

The result is

I lOve yOu

This result reminds us

1.strtr is case-sensitive
2.strtr replacement is very special, please pay attention to the yOu at the back, in the middle The O is replaced, which is obviously not our intention

Give another special example to illustrate the weirdness of this php sttr function

<ol class="dp-xml"><li class="alt"><span><span class="tag">< ?</span><span class="tag-name">php</span><span> </span></span></li><li><span>echo strtr("I Love <br />you","Love","");  </span></li><li class="alt"><span class="tag">?></span><span>   </span></span></li></ol>

The result is

I Love you

PHP string replacement will not change anything, so strtr needs to pay attention to:

3. It cannot be replaced with empty, that is, the last parameter It cannot be an empty string, of course spaces are allowed.

Another example of strtr function

<ol class="dp-xml"><li class="alt"><span><span class="tag">< ?</span><span class="tag-name">php</span><span> </span></span></li><li><span>echo strtr("I Loves you","Love","lOvEA");  </span></li><li class="alt"><span class="tag">?></span><span>   </span></span></li></ol>

The result is

I lOvEs yOu

Pay attention to Chapter 1 The three-parameter A does not appear in the result

4. I do not recommend using strtr to exchange less for more

ok. 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

5. When you can use the strtr function for PHP string replacement, you must use it

Then How to use it comfortably?
This is its second case
strtr(string,array)

6. How to use strtr as you wish

<ol class="dp-xml">
<li class="alt"><span><span class="tag">< ?</span><span class="tag-name">php</span><span> </span></span></li><li><span>$</span><span class="attribute">table_change</span><span> = </span><span class="attribute-value">array</span><span>('you'=</span><span class="tag">></span><span>'her sister');  </span></span></li>
<li class="alt"><span>echo strtr("I Love you",$table_change);  </span></li>
<li>
<span class="tag">?></span><span>   </span>
</li>
<li class="alt"><span> </span></li>
</ol>

The result is
I Love her sister

7. Tips: If you think of PHP string replacement, just add whatever you want to the array

For example

<ol class="dp-xml">
<li class="alt"><span><span class="tag">< ?</span><span class="tag-name">php</span><span> </span></span></li><li><span>$</span><span class="attribute">table_change</span><span> = </span><span class="attribute-value">array</span><span>('you'=</span><span class="tag">></span><span>'her sister');  </span></span></li>
<li class="alt">
<span>$table_change += array('Love' =</span><span class="tag">></span><span> 'hate');  </span>
</li>
<li><span>echo strtr("I Love you",$table_change);  </span></li>
<li class="alt">
<span class="tag">?></span><span>   </span>
</li>
</ol>

The result is

I hate her sister

Remind me again that Love written as love will not work.

Okay, I talked a lot. In fact, what I want to say most about strtr is the usage behind it.
It is simple and convenient.
It seems that the later usage also ignores the problem of different character lengths before and after

The above PHP string replacement experiment, PHP5.2 passed the test.

http://www.bkjia.com/PHPjc/446240.htmlwww.bkjia.comtruehttp: //www.bkjia.com/PHPjc/446240.htmlTechArticleIn actual programming, when we want to implement string replacement, we usually use strtr() function. Now let’s explain in detail how to implement string replacement in PHP. ...