Summary of PHP string replacement functions

As a powerful programming language, PHP provides a wealth of string processing functions. With the development of the Internet, string processing has increasingly become an indispensable part of Web development. In PHP, the string replacement function is used to search and replace specific text in a string. The following is a summary of commonly used string replacement functions in PHP.

1. str_replace

The str_replace function is one of the most commonly used string replacement functions in PHP. It can replace a certain substring in a string. The syntax of this function is as follows:

str_replace($search, $replace, $string [, &$count])

Among them, $search represents the substring that needs to be replaced, $replace represents the string to be replaced, $string represents the original string that needs to be replaced, and $count represents the optional parameters. , returns the number of times it has been replaced.

For example:

$text = "Hello World!";
$new_text = str_replace("World", "PHP", $text);
echo $new_text;

The output result is:

Hello PHP!

2. str_ireplace

The str_ireplace function is similar to the str_replace function, but it does not case sensitive. The syntax of this function is as follows:

str_ireplace($search, $replace, $string [, &$count])

Among them, $search and $replace are the same as the str_replace function.

For example:

$text = "Hello World!";
$new_text = str_ireplace("world", "PHP", $text);
echo $new_text;

The output result is:

Hello PHP!

3. preg_replace

The preg_replace function is a powerful string in PHP Replace function, which searches and replaces strings using regular expressions. The syntax of this function is as follows:

preg_replace($pattern, $replacement, $string [, $limit [, &$count]])

Among them, $pattern represents the pattern of the regular expression, $replacement represents the string to be replaced, $string represents the original string that needs to be replaced, and $limit is an optional parameter, specified The maximum number of times to be replaced, $count means returning the number of times replaced.

For example:

$text = "I have 3 cats and 2 dogs.";
$new_text = preg_replace("/d+/", "5", $text);
echo $new_text;

The output is:

I have 5 cats and 5 dogs.

4. strtr

The strtr function is a simple but effective string replacement Function that passes replacement rules as an array. The syntax of this function is as follows:

strtr($string, $replace_pairs)

Among them, $string represents the original string that needs to be replaced, and $replace_pairs represents the rules that need to be replaced in the form of key-value pairs.

For example:

$text = "The quick brown fox jumps over the lazy dog.";
$new_text = strtr($text, "eoau", "1234");
echo $new_text;

The output result is:

Th2 q5ick br4wn f1x j3mps 4v5r th1 l1zy d4g.

5. mb_str_replace

The mb_str_replace function is similar to the str_replace function, but it can Handles multi-byte character sets, especially suitable for Chinese string replacement. The syntax of this function is as follows:

mb_str_replace($search, $replace, $string)

Among them, $search represents the string that needs to be replaced, $replace represents the string that needs to be replaced, and $string represents the original string that needs to be replaced.

For example:

$text = "你好，世界！";
$new_text = mb_str_replace("世界", "PHP", $text);
echo $new_text;

The output result is:

你好，PHP！

Summary:

The above introduces the commonly used string replacement functions in PHP, including str_replace, str_ireplace , preg_replace, strtr and mb_str_replace. In web development, proper use of these functions can make string processing faster and easier.

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