如何在JavaScript中检查字符 [英] How to check a character in javascript

问题描述

如何在javascript中检查字符是小写字母还是大写字母

How can i check a character whether it is small letter or captial letter in javascript

推荐答案

一种方法是执行以下操作:

One way is to do this:

string a = "a";
if (a == a.toUpperCase())
{
    // it's uppercase
}

另一种方法是使用正则表达式:

Another way is with regular expressions:

var check = /[:upper:]/;
alert(check.test("R")); // returns true
alert(check.test("r")); // returns false

一种方法通过使用toLowerCase()和toUpperCase()函数可以做到这一点.您可以使用这两个函数，将每个结果分配给一个单独的变量，然后与原始字符进行比较.如果原始字符等于toLowerCase()的结果，则其为小写字母，否则为大写字母.希望你能明白.

One way of doing it is by using toLowerCase() and toUpperCase() functions. You can use the two functions, assign each result to a separate variable, and then compare to the original character. If original character is equal to the result of toLowerCase(), then its a lower case, else, upper case. Hope you get the idea.

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