不区分大小写的搜索 [英] Case-insensitive search

问题描述

我正在尝试使用JavaScript中的两个字符串进行不区分大小写的搜索。

I'm trying to get a case-insensitive search with two strings in JavaScript working.

通常它会是这样的：

var string="Stackoverflow is the BEST";
var result= string.search(/best/i);
alert(result);

/ i 标志用于案例 - 不敏感。

The /i flag would be for case-insensitive.

但我需要搜索第二个字符串;没有旗帜它完美无缺：

But I need to search for a second string; without the flag it works perfect:

var string="Stackoverflow is the BEST";
var searchstring="best";
var result= string.search(searchstring);
alert(result);

如果我将 / i 标志添加到上面的例子它将搜索searchstring而不是变量searchstring中的内容（下一个例子不起作用）：

If I add the /i flag to the above example it would search for searchstring and not for what is in the variable "searchstring" (next example not working):

var string="Stackoverflow is the BEST";
var searchstring="best";
var result= string.search(/searchstring/i);
alert(result);

我如何实现这一目标？

推荐答案

是的，使用 .match ，而不是 .search 。 .match 调用的结果将返回与其自身匹配的实际字符串，但它仍可用作布尔值。

Yeah, use .match, rather than .search. The result from the .match call will return the actual string that was matched itself, but it can still be used as a boolean value.

var string = "Stackoverflow is the BEST";
var result = string.match(/best/i);
// result == 'BEST';

if (result){
    alert('Matched');
}

使用这样的正则表达式可能是最简洁，最明显的方法在JavaScript中，但请记住它是正则表达式，因此可以包含正则表达式元字符。如果你想从其他地方获取字符串（例如，用户输入），或者如果你想避免必须逃避许多元字符，那么你最好使用 indexOf 像这样：

Using a regular expression like that is probably the tidiest and most obvious way to do that in JavaScript, but bear in mind it is a regular expression, and thus can contain regex metacharacters. If you want to take the string from elsewhere (eg, user input), or if you want to avoid having to escape a lot of metacharacters, then you're probably best using indexOf like this:

matchString = 'best';
// If the match string is coming from user input you could do
// matchString = userInput.toLowerCase() here.

if (string.toLowerCase().indexOf(matchString) != -1){
    alert('Matched');
}

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