What are the 7 PHP string processing functions?

The seven PHP string processing functions include strlen(), strpos(), substr(), str_replace(), strtolower(), strtoupper(), trim(), etc. Detailed introduction: 1. strlen(), used to obtain the length of a string; 2. strpos(), used to find a specific substring in a string and return the first occurrence position; 3. substr(), used to obtain Substring of string; 4. str_replace(), etc.

Operating system for this tutorial: Windows 10 system, PHP8.1.3 version, Dell G3 computer.

In PHP, there are many functions that can be used for string processing. The following are 7 commonly used PHP string processing functions:

1. strlen(): is used to obtain the length of a string. It accepts a string as argument and returns the number of characters in the string. For example:

$str = "Hello World";
$length = strlen($str);
echo $length; // 输出 11

2, strpos(): is used to find a specific substring in a string and return the position of the first occurrence. It accepts two parameters, the string to be found and the substring to be found. If the substring is found, returns the position of the substring in the string; if not found, returns false. For example:

$str = "Hello World";
$pos = strpos($str, "World");
echo $pos; // 输出 6

3, substr(): is used to obtain the substring of a string. It accepts three parameters, namely the string to be intercepted, the starting position and the interception length. The starting position can be positive (counting from left to right) or negative (counting from right to left). For example:

$str = "Hello World";
$sub = substr($str, 6, 5);
echo $sub; // 输出 World

4, str_replace(): is used to replace a specific substring in a string. It accepts three parameters, namely the substring to be replaced, the substring after replacement and the string to be replaced. It replaces all matching substrings with the specified substring. For example:

$str = "Hello World";
$newStr = str_replace("World", "PHP", $str);
echo $newStr; // 输出 Hello PHP

5, strtolower(): is used to convert the string to lowercase. It accepts a string as argument and returns the converted string. For example:

$str = "Hello World";
$newStr = strtolower($str);
echo $newStr; // 输出 hello world

6, strtoupper(): is used to convert the string to uppercase. It accepts a string as argument and returns the converted string. For example:

$str = "Hello World";
$newStr = strtoupper($str);
echo $newStr; // 输出 HELLO WORLD

7, trim(): is used to remove spaces or specified characters at both ends of the string. It accepts two parameters, the string to be processed and optional specified characters. If the specified character is not specified, spaces will be removed by default. For example:

$str = "   Hello World   ";
$newStr = trim($str);
echo $newStr; // 输出 Hello World

These are commonly used string processing functions in PHP. They can help us process the length of strings, find substrings, intercept substrings, replace substrings, and convert case. In actual development, we can choose the appropriate function to process strings according to specific needs.

The above is the detailed content of What are the 7 PHP string processing functions?. For more information, please follow other related articles on the PHP Chinese website!