PHP can easily intercept mixed Chinese and English strings with just 2 lines of code!

PHP can easily intercept mixed Chinese and English strings with just 2 lines of code! _PHP Tutorial

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Release： 2016-07-13 10:29:19

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When it comes to Chinese and English mixed counting and interception, the first thing that comes to mind is ascii, hexadecimal, regular matching, and loop counting.

Today I will share with you the mb extension of php to teach you how to process strings easily.

Let me introduce to you the functions used:

mb_strwidth($str, $encoding) returns the width of the string

$str The string to be calculated

$encoding The encoding to use, such as utf8, gbk

mb_strimwidth($str, $start, $width, $tail, $encoding) intercepts string according to width

$str The string to be intercepted

$start From which position to intercept, the default is 0

$width The width to be intercepted

$tail is appended to the string after the intercepted string, commonly used is...

$encoding The encoding to use

I will give you an example below:

<?<span>php
</span><span>/*</span><span>*
 * utf8 编码格式
 * 1个中文占用3个字节
 * 我们希望的是1个中文占用2个字节，
 * 因为从宽度上看2个英文字母占用的位置相当于1个中文
 </span><span>*/</span>

<span>//</span><span> 测试字符串</span>
<span>$str</span> = 'aaaa啊啊aaaa啊啊啊aaa'<span>;
</span><span>echo</span> <span>strlen</span>(<span>$str</span>); <span>//</span><span> 只用strlen输出为25个字节

// 必须指定编码，不然会使用php的内码 mb_internal_encoding()可以查看内码
// 使用mb_strwidth输出字符串的宽度为20使用utf8编码</span>
<span>echo</span> mb_strwidth(<span>$str</span>, 'utf8'<span>); 

</span><span>//</span><span> 只有宽度大于10才截取</span>
<span>if</span>(mb_strwidth(<span>$str</span>, 'utf8')>10<span>){
    </span><span>//</span><span> 此处设定从0开始截取，取10个追加...，使用utf8编码
    // 注意追加的...也会被计算到长度之内</span>
    <span>$str</span> = mb_strimwidth(<span>$str</span>, 0, 10, '...', 'utf8'<span>);
}

</span><span>//</span><span> 最后输出 aaaa啊... 4个a算4个 1个啊算2个 3个点算3个 4+2+3=9
// 是不是很简单啊，有的人说了为什么是9个不是10个吗？
// 因为正好&ldquo;啊&rdquo;的后边还是&ldquo;啊&rdquo;，中文算2个，9+2=11 超出了设定，所以去掉1个就是9了</span>
<span>echo</span> <span>$str</span>;

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Let me introduce some other functions to you:

mb_strlen($str, $encoding) returns the length of the string

$str The string to be calculated

$encoding The encoding used

mb_substr($str, $start, $length, $encoding) intercepts the string

$str The string to be intercepted

$start Where to start intercepting

$length intercepts the length

$encoding The encoding used

In fact, these two functions are very similar to strlen() and substr(). The only difference is that the encoding can be set.

Example below:

<?<span>php
</span><span>/*</span><span>*
 * utf8 编码格式
 * 1个中文占用3个字节
 </span><span>*/</span>
<span>$str</span> = 'aa12啊aa'<span>;
</span><span>echo</span> <span>strlen</span>(<span>$str</span>); <span>//</span><span> 直接输出长度为9

// 输出长度为7，为什么是7呢？
// 注意这里设定编码以后，不管是中文还是英文每个长度都为1
// a a 1 2 啊 a a 
// 1+1+1+1+1+1+1 = 7
// 是不是正好7个字符啊</span>
<span>echo</span> mb_strlen(<span>$str</span>, 'utf8'<span>);

</span><span>//</span><span> 同样mb_substr也是一样的
// 我现在只想要5个字符</span>
<span>echo</span> mb_substr(<span>$str</span>, 0, 5, 'utf8'); <span>//</span><span> 输出 aa12啊</span>

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In fact, there are many useful functions in the mb extension, so I won’t list them all here.

Interested friends can view the official manual

http://www.php.net/manual/zh/ref.mbstring.php

Okay, that’s all for today.