Javascript变量中的多个值 [英] Javascript multiple values in variable

问题描述

有没有办法让一个变量具有多个这样的值：

Is there any way to have one variable with multiple values like this:

var variable = 1, 2, 3;
var enteredVal = 1;

if (enteredVal == variable){
    alert('You chose the right number');
}

因此，如果变量enteredVal等于1,2或3，它将提醒消息。
我似乎无法理解它。

So if the variable enteredVal is equal to 1, 2 or 3, it will alert the message. I can't seem to get my head around it.

推荐答案

无法分配多个不同的值单个变量。

There is no way to assign multiple distinct values to a single variable.

另一种方法是让变量成为 数组 ，你可以查到看看 enterval 是否在数组中。

An alternative is to have variable be an Array, and you can check to see if enteredval is in the array.

var variable = [1, 2, 3];
var enteredval = 1;

if (variable.indexOf(enteredval) > -1){
    alert('you chose the right number');
}

请注意 indexOf 是在IE8及以下版本中无法使用（请参阅要求在底部）。在这种情况下，您需要使用框架/库的方法，或自己编写：

Note that indexOf on an array is not usable in IE8 and below (see the Requirements section at the bottom). In that case you would need to use a framework/library's method, or write it yourself:

var variable = [1, 2, 3];
var enteredval = 1;

for (var i = 0; i < variable.length; i++) {
    if (variable[i] === enteredval) {
        alert('you chose the right number');
        break; // No need to check all the other values in variable
    }
}

要在实例化后修改数组，请查看 push ， pop ， shift ， unshift 。要修改现有值，您可以直接访问索引并重新分配值。

To modify arrays after you have instantiated them, take a look at push, pop, shift, and unshift for adding/removing values. For modifying existing values, you can directly access the index and reassign the value.

variable[1] = 5;
// variable is now [1, 5, 3] since arrays are 0-indexed

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