使用JavaScript比较两个日期不能按预期工作 [英] Comparing two dates using JavaScript not working as expected

问题描述

这是我的JavaScript代码：

Here is my javascript code:

var prevDate = new Date('1/25/2011'); // the string contains a date which
                                      // comes from a server-side script
                                      // may/may not be the same as current date

var currDate = new Date();            // this variable contains current date
    currDate.setHours(0, 0, 0, 0);    // the time portion is zeroed-out

console.log(prevDate);                // Tue Jan 25 2011 00:00:00 GMT+0500 (West Asia Standard Time)
console.log(currDate);                // Tue Jan 25 2011 00:00:00 GMT+0500 (West Asia Standard Time)
console.log(prevDate == currDate);    // false -- why oh why

请注意，两个日期是一样的，但使用 == 表示它们不一样。为什么？

Notice that both dates are the same but comparing using == indicates they are not the same. Why?

推荐答案

我不认为你可以使用 == 比较JavaScript中的日期。这是因为它们是两个不同的对象，所以它们不是对象相等。 JavaScript允许您使用 == 比较字符串和数字，但所有其他类型都作为对象进行比较。

I don't think you can use == to compare dates in JavaScript. This is because they are two different objects, so they are not "object-equal". JavaScript lets you compare strings and numbers using ==, but all other types are compared as objects.

：

var foo = "asdf";
var bar = "asdf";
console.log(foo == bar); //prints true

foo = new Date();
bar = new Date(foo);
console.log(foo == bar); //prints false

foo = bar;
console.log(foo == bar); //prints true

但是，您可以使用 getTime 方法获取可比较的数值：

However, you can use the getTime method to get comparable numeric values:

foo = new Date();
bar = new Date(foo);
console.log(foo.getTime() == bar.getTime()); //prints true

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