How to verify whether input is uppercase letters in golang

Golang is a high-performance, modern programming language that often involves string processing in daily development. Among them, validating whether the input is in uppercase letters is a common requirement. This article will introduce how to verify whether the input is uppercase letters in Golang.

Method 1: Use the unicode package

The unicode package in Golang provides a series of functions to determine the encoding type of characters. For uppercase letters, the corresponding encoding range is 65-90 (decimal), so we can use the IsUpper function in the unicode package to determine whether the character is an uppercase letter. An example is as follows:

import (
    "unicode"
)

func isUpper(s string) bool {
    for _, r := range s {
        if !unicode.IsUpper(r) {
            return false
        }
    }
    return true
}

In the function, we iterate through each character in the input string and use the IsUpper function to determine whether the character is an uppercase letter. If a non-uppercase character is encountered, false is returned directly, indicating that there are lowercase letters or other characters in the input string. Returns true if all characters are uppercase letters, indicating that the input string contains only uppercase letters.

Method 2: Use regular expressions

Regular expressions in Golang can be used to determine whether a string matches a certain pattern. For the judgment of uppercase letters, we can use regular expressions to match uppercase letters. An example is as follows:

import (
    "regexp"
)

func isUpper(s string) bool {
    match, _ := regexp.MatchString("^[A-Z]+$", s)
    return match
}

In the function, we use the regular expression "^[A-Z] $" to match the input string. Among them, the ^ and $ symbols represent the beginning and end of the entire string, and [A-Z] represents the range of uppercase letters, which means matching one or more characters. If the input string contains only uppercase letters, the match is successful and true is returned; otherwise, the match fails and false is returned.

Summary

The above are two methods of verifying whether the input is uppercase letters in Golang. Using the unicode package can more flexibly determine character types, and using regular expressions can more easily match strings that match a certain pattern. In actual development, you can choose which method to use based on specific circumstances.

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