javascript 与多个值进行比较的简洁方法

Concise way to compare against multiple values

提问by FatDogMark

Consider the following:

考虑以下：

var a = 'jesus';

if(a == 'something' || a == 'nothing' || a=='anything' || a=='everything'){
   alert('Who cares?');
}

Is there a way to make this shorter?

有没有办法缩短这个时间？

Is there anything in Javascript like if (a=='bbb'||'ccc')?

Javascript 中有什么东西if (a=='bbb'||'ccc')吗？

In addition, can jQuery help here?

另外，jQuery 能帮上忙吗？

采纳答案by Christophe

With a regex:

使用正则表达式：

if (/^(something|nothing|anything|everything)$/.exec('jesus')) alert('Who cares?');?

Or the opposite:

或者相反：

/^(something|nothing|anything|everything)$/.exec('jesus')||alert('Who cares?');?

[Update] Even shorter ;-)

[更新] 更短;-)

if (/^(some|no|any|every)thing$/.exec('jesus')) alert('Who cares?');?

回答by alex

You could use this...

你可以用这个...

if (["something", "nothing", "anything", "everything"].includes(a)) {
   alert('Who cares?');
}

If you're stuck with older browser support...

如果您坚持使用较旧的浏览器支持...

if (["something", "nothing", "anything", "everything"].indexOf(a) > -1) {
   alert('Who cares?');
}

You also tagged it jQuery, so if you need to support older browsers without Array.prototype.indexOf(), you could use $.inArray().

您还将它标记为 jQuery，因此如果您需要支持不带 的旧浏览器Array.prototype.indexOf()，则可以使用$.inArray().

回答by Adil

You can put the options in array and use jQuery $.inArray()or javascrpt indexOf()to search array

您可以将选项放在数组中并使用 jQuery$.inArray()或 javascrptindexOf()来搜索数组

Pure javascript?

纯javascript？

Live Demo

现场演示

var a = 'anything';
arr = ['something', 'nothing', 'anything', 'everything'];
if(arr.indexOf(a) != -1)
    alert("condition met");    
else
    alert("condition not met");    

With jQuery

使用 jQuery

Live Demo

现场演示

var a = 'jesus';
arr = ['something', 'nothing', 'anything', 'everything'];

if($.inArray(a, arr) != -1) // With jQuery
    alert("condition met");    
else
    alert("condition not met");    

回答by Maciej Bukowski

With ES7 you are able to use Array.prototype.includesand even shorter notation than indexOf, which is already implemented in every modern browser.

使用 ES7，您可以使用Array.prototype.includes甚至比 indexOf 更短的符号，它已经在每个现代浏览器中实现。

Here is the example usage:

这是示例用法：

if (['hero', 'anything', 'everything'].includes(me)) {
    alert('Who cares?');
}

And the polyfillfrom Mozilla.

还有来自 Mozilla的polyfill。

回答by suresh.g

Try this:

试试这个：

If you want to check the words other than Jesus, try following,

如果您想检查耶稣以外的词，请尝试以下，

if(a != "jesus"){
   alert('Who cares?');
}

if you want to check particular words, try following,

如果您想检查特定单词，请尝试以下操作，

var check_arrays = ['something','nothing', 'anything', 'everything'];
if(checkThis(a)){
   alert('Who cares?');
}

function checkThis(a)
{
   for(i=0;i<check_arrays.length;i++)
   {
      if(check_arrays[i] == a)
      return true;
   }
   return false;
}

回答by Akhil Sekharan

May be using switch instead of if:

可能正在使用 switch 而不是 if：

var a = 'jesus';
switch (a){
    case 'something':
    case 'nothing' :
    case 'anything':
    case 'everything':
   alert('Who cares?');
   break;
}

回答by Christophe

Using an object literal:

使用对象字面量：

var all={something:1,nothing:1,anything:1,everything:1};
if (all.hasOwnProperty('jesus')) alert('Who cares?');?

I'd say this is the most concise cross-browser expression for general use (well, as long as the objective is to compare strings). It is also very flexible as you can easily add or remove properties:

我会说这是一般用途的最简洁的跨浏览器表达式（好吧，只要目标是比较字符串）。它也非常灵活，因为您可以轻松添加或删除属性：

all.mything=1;
delete all.nothing;

回答by Miqdad Ali

I think there is no easy method to do this. But you can write a function in_arrayand you can use it anywhere you need

我认为没有简单的方法可以做到这一点。但是你可以写一个函数in_array，你可以在任何你需要的地方使用它

Array.prototype.in_array = function(p_val) {
    for(var i = 0, l = this.length; i < l; i++) {
        if(this[i] == p_val) {
            return true;
        }
    }
    return false;
}

var v_array = [ 'something','nothing', 'anything', 'everything'];

var a = "jesus";

if(v_array.in_array(a)){
    alert('Who cares?');
}