Using PHP strlen() to Get String Length

PHP is a popular server‑side language that provides many built‑in functions for string handling, among which strlen is commonly used to obtain the length of a string.

The length refers to the number of characters (bytes) in the string. By calling strlen($str) and passing the target string as an argument, the function returns its length. The following example demonstrates this:

The script first defines $str with the value "Hello World!" , then calls strlen to compute its length, stores the result in $length , and finally outputs the length with echo .

Running the code produces:

字符串"Hello World!"的长度是：12

The strlen function is simple and convenient: it returns the number of bytes in the string. For single‑byte encodings such as ASCII or UTF‑8 this matches the character count, but for multibyte characters (e.g., Chinese) the byte count may differ, so developers should be aware of the string’s encoding when using strlen .

In summary, strlen is a useful tool for obtaining string length in PHP scripts and applications, provided the encoding considerations are taken into account.