Introduction to PHP functions: strlen() function

PHP function introduction: strlen() function

The strlen() function is a commonly used string processing function in PHP. Its function is to calculate the length of a string. (Including spaces and special characters, but not null characters).

The syntax format of the strlen() function is as follows:

int strlen ( string $string )

Among them, $string represents the string whose length is to be calculated.

Below, let’s look at some specific code examples:

Example 1: Calculate the length of the string

$str = "Hello, world!"; //定义一个字符串
echo strlen($str); //输出字符串的长度

The output result is:

13

Example 2: Calculate the length of the string by ignoring spaces

$str = "   Hello,   world!    "; //定义一个带有空格的字符串
echo strlen($str); //输出字符串的长度
echo strlen(trim($str)); //输出去除空格后字符串的长度

The output result is:

23
13

As can be seen from the above example, the strlen() function is very commonly used when processing strings. It can quickly count the length of strings. It is not only suitable for regular string processing tasks, but also can be applied to different application scenarios, such as the length limit of user nicknames in social networking sites, the length limit of product names in shopping malls, etc.

It should be noted that the strlen() function only supports processing UTF-8 and ISO-8859-1 encoded strings, and calculation errors may occur for strings in other encoding formats.

When using the strlen() function, you also need to pay attention to whether the string contains special characters or Chinese characters, because they occupy different numbers of bytes in different encoding formats, which will affect the string. Length calculation result.

The above is a detailed introduction and code example of the strlen() function. I hope it will be helpful to everyone.

The above is the detailed content of Introduction to PHP functions: strlen() function. For more information, please follow other related articles on the PHP Chinese website!