How to use PHP regular expressions to validate mixed Chinese and English input

In today's Internet era, mixed input of Chinese and English has become an indispensable part of our daily lives. However, during the website development process, the data entered by the user must be verified to ensure the legality and security of the data. Therefore, this article will introduce how to use PHP regular expressions to verify mixed input in Chinese and English.

1. What is a regular expression

Before introducing how to use PHP regular expressions to verify mixed input in Chinese and English, we need to first understand what a regular expression is. Regular expression (Regular Expression) is a tool for text matching and processing, which is widely used in various programming languages. Regular expressions consist of a series of characters and operators used to describe the characteristics and patterns of strings. Regular expressions can be used to match characters, words, lines, etc. in text to achieve a specific operation purpose.

2. Verify Chinese input

In PHP, you can use the following code to use regular expressions to verify Chinese input:

preg_match("/^[x{4e00}-x{9fa5}]+$/u", $str)

The above regular expression uses the Unicode encoding range, Matches all Chinese characters.

Use slashes (/.../) at the beginning and end of the regular expression to identify the regular expression, and use "x{4e00}-x{9fa5}" in the middle to match the range All characters in the Unicode encoding, the "u" modifier is used at the end, indicating the Unicode encoding.

3. Verify English input

In PHP, you can use the following code to use regular expressions to verify English input:

preg_match("/^[A-Za-z]+$/", $str)

The above regular expression matches the input string of English letters, where "A-Z" matches all uppercase letters and "a-z" matches all lowercase letters.

4. Verify Chinese and English mixed input

Next, we will introduce how to use regular expressions to verify Chinese and English mixed input. You can use the following code:

preg_match("/^[x{4e00}-x{9fa5}A-Za-z]+$/u", $str)

The above code uses the regular expressions for Chinese and English verification introduced earlier. By merging the two regular expressions, it matches mixed input of Chinese and English.

Among them, the " " operator is used to match one or more characters, and the two character types "[x{4e00}-x{9fa5}]" and "[A-Za-z]" are used The "|" operator represents the OR relationship.

5. Usage Example

The following is an example of using PHP regular expressions to verify Chinese and English input:

$str = "Hello, 世界！";
if (preg_match("/^[x{4e00}-x{9fa5}A-Za-z]+$/u", $str)) {
    echo "输入符合要求。";
} else {
    echo "输入不符合要求。";
}

The above code will output "The input meets the requirements.", because The input string contains legal Chinese and English characters.

6. Summary

By using PHP regular expressions to verify Chinese and English mixed input, the legality and security of user input data can be effectively guaranteed. In actual development, regular expressions can be adjusted according to specific needs to match the actual situation.

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