Why these two dates are not equal in javascript?

Question

I'm comparing two dates in objA and objB, and they are not equal as the following console output shows.
Can't understand why..

objA[keysA[i]]
Sun Sep 25 2016 00:00:00 GMT+0900 (KST)
objB[keysA[i]]
Sun Sep 25 2016 00:00:00 GMT+0900 (KST)
typeof objA[keysA[i]]
"object"
typeof objB[keysA[i]]
"object"
objA[keysA[i]] !== objB[keysA[i]]
true

because dates are an object you can not compare them like that ... try objA[keysA[i]]+0 !== objB[keysA[i]]+0 which coerces the dates to a Number — Jaromanda X
– Jaromanda X, Commented Oct 26, 2016 at 3:48

Indiana Kernick · Accepted Answer · 2016-10-26 03:52:47Z

1

In JavaScript you compare objects by reference.

let a = {};
let b = {};
let c = a;

a == b //false
a == c //true

A simple way of comparing objects is to convert them to a string and compare the string. You can use Date.prototype.toString to compare Date objects like this

objA[keysA[i]].toString() !== objB[keysA[i]]].toString() //false

answered Oct 26, 2016 at 3:52

Indiana Kernick

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Comments

James111 · Accepted Answer · 2016-10-26 03:50:22Z

1

You'll need to stringify the dates & compare them that way. For example:

var date1 = new Date(); 
var date2 = new Date();

console.log (date1==date2); // This will print false

But if we stringify the dates and compare them that way this will become true, like so:

console.log (date1.toString() === date2.toString())

answered Oct 26, 2016 at 3:50

James111

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2 Comments

Jaromanda X Over a year ago

date1+0 === date2+0 as well - and accounts for millisecond differences

James111 Over a year ago

Yep. @JaromandaX - If you were to do date1+0 === date2+0 | It'd = true as you said.

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