如何在正则表达式中表示双引号字符(")? [英] How to represent the double quotes character (") in regex?

问题描述

我需要使用正则表达式来检查字符串是否以 双引号 字符 (") 开头并以 双引号 结尾角色也是.

I need to use regex, to check if a string starts with a double quotes character (") and ends with a double quotes character too.

问题是我不能使用 双引号 字符，因为它会混淆.有没有其他方法可以在正则表达式或一般字符串中表示 双引号 字符 "?

The problem is I can't use a double quotes character, cause it gets confused. Is there any other way to represent a double quotes character " in regex, or in string in general?

String s = """;    // ?

推荐答案

首先，双引号字符在正则表达式中并没有什么特别之处——它只是另一个字符，所以它不需要转义从正则表达式的角度来看.

Firstly, double quote character is nothing special in regex - it's just another character, so it doesn't need escaping from the perspective of regex.

但是，由于Java使用双引号分隔字符串常量，如果你想在Java中创建一个带有双引号的字符串，你必须将它们转义.

However, because Java uses double quotes to delimit String constants, if you want to create a string in Java with a double quote in it, you must escape them.

此代码将测试您的字符串是否匹配:

This code will test if your String matches:

if (str.matches("".*"")) {
    // this string starts and end with a double quote
}

请注意，您不需要添加 start 和 end 的输入标记(^ 和 $) 在正则表达式中，因为 matches() 要求匹配整个输入以返回 true - ^ 和 $ 是隐含的.

Note that you don't need to add start and end of input markers (^ and $) in the regex, because matches() requires that the whole input be matched to return true - ^ and $ are implied.

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