How to calculate string length in php? Comparison of two methods

How to calculate string length in php? The following article will introduce to you two built-in functions strlen() and mb_strlen() in PHP to calculate the length of strings, and see their differences.

Use the strlen() function

to return the length of the given string string.

Return value: If successful, the length of the string string is returned; if string is empty, returns 0.

Examples based on interview questions:

   $str = 'hello';
   echo strlen($str), &#39;<br>&#39;; //5
   
   $str1 = &#39;中国&#39;;
   echo strlen($str1), &#39;<br>&#39;; //6

   echo strlen($str4), &#39;<br>&#39;; //0

UTF-8 encodes a Chinese character and occupies 3 bytes gdk encodes a Chinese character and occupies 2 bytes

The following is the gdk encoding

$str2 = 'hello';
echo strlen($str2), &#39;<br>&#39;; //5
$str3 = &#39;中国&#39;;
echo strlen($str3), &#39;<br>&#39;; //4

echo strlen($str4), &#39;<br>&#39;; //0

Use the mb_strlen() function

—Get the length of the string

Return value: Return the number of characters contained in the string str with encoding encoding . Returns FALSE if the given encoding is invalid. encoding is the character encoding.

$str = '你好中国'; 
echo strlen($str), &#39;<br>&#39;; //12
$str1 = &#39;你好中国&#39;;
echo mb_strlen($str1, &#39;utf-8&#39;), &#39;<br>&#39;; //4

gbk Two bytes and one character

strlen is the calculation of string 'byte' length - string length

mb_strlen is to calculate the length of string 'characters'

Recommended learning: "PHP Video Tutorial"

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