How to use PHP regular expressions to verify whether the input string is in the correct name or screen name format

In today's social media and digital era, online names have become a part of people's daily lives and an important way for people to show their personality socially. In the screen name or name, the presence of some special symbols, numbers and other elements will affect the legitimacy of the name or screen name. Therefore, in order to ensure the correct format of the name or screen name, the input string can be verified through PHP regular expressions.

PHP regular expression is a method of matching and replacing text. Regular expressions can match a string of a certain pattern and then verify whether the string conforms to a certain format. In the verification of name or screen name, PHP regular expression will verify the input string to determine whether it meets certain rules.

The following will introduce some commonly used PHP regular expression verification rules for verifying the legitimacy of names or screen names.

1. Verify Chinese name

Chinese name refers to a name composed of two or more Chinese characters. Regarding the verification rules for Chinese names, you can use the following regular expressions:

/^[x{4e00}-x{9fa5}]{2,}$/u

Among them, "x{4e00}" represents the starting value of the Unicode encoding of Chinese characters, and "x{9fa5}" represents the Unicode encoding of Chinese characters. end value. "u" means enable UTF-8 support.

Using the above regular expression, you can verify whether the input string consists of two or more Chinese characters.

2. Verification of English Internet Names

In the verification of English Internet names, it is usually necessary to determine whether the following rules are met:

• Internet name The length is between 3-20 characters
• The screen name can contain letters, numbers, spaces, _ and - and other special characters

Therefore, you can use the following regular expression for verification :

/^[a-zA-Z0-9_-]{3,20}$/u

Among them, "[a-zA-Z0-9_-]" means that special characters such as numbers, uppercase and lowercase letters, "_" and "-" are allowed. "{3,20}" indicates that the length of the network name is between 3-20 characters.

3. Verify Chinese and English mixed network names

For verification of Chinese and English mixed network names, you can use the following regular expression:

/^[a-zA-Z0-9_x{4e00}-x{9fa5}]{3,20}$/u

where "x {4e00}" and "x{9fa5}" represent the starting and ending values ​​of Unicode encoding of Chinese characters. The above regular expression allows the use of numbers, letters, Chinese characters and the "_" special character.

It should be noted that PHP regular expression verification is not omnipotent, nor may it meet all verification needs. For example, the above regular expression cannot determine whether the space between a person's name conforms to conventional habits. In practical applications, specific regular expressions can be written for verification based on specific needs.

In addition to regular expressions, you can also use other string functions in PHP to determine the legitimacy of a name or screen name, such as the strlen() function or preg_match() function, etc. Different verification methods can be selected according to different situations.

In short, PHP regular expression verification is a universal and effective verification method, which plays an important role in ensuring the legitimacy of names or screen names. In actual development, the appropriate verification method can be selected according to the specific situation to ensure the correctness of the information input.

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