在node.js中将整数转换为Date

Question

I'm trying to convert a integer to a Date using node .js, and Date.

I know that this is a very common question but all the solutions that have been posted before have failed to help me.

I am getting the dates from a json file found at http://api.guardian.gg/chart/elo/4611686018432537994 ,

Example date: 1461110400000

What I've tried:

    var date = String(new Date(elodata.x));

and

    var date = String(new Date(parseInt(elodata.x)));

But I get invalid date as a result.

I realise that this might not be doable because I don't know how guardian.gg handles this data. But you never know.

Answer 1

You can pass in your value directly to a Date constructor in Javascript if it is an integer (which it appears to be in :

var date = new Date(elodata.x);

Likewise, you can also use the the setTime() function in Javascript to pass your integer value in if you already have an existing object :

var date = new Date();
d.setTime(elodata.x);

Example

 var d1 = new Date(1461110400000); console.log(`Constructor: ${d1}`); var d2 = new Date(); d2.setTime(1461110400000); console.log(`setTime(): ${d2}`); 

Answer 2

When a single argument is passed to the Date constructor, if it's a string it will be parsed. The result of that is implementation dependent but if 1461110400000 is a string it will almost certainly give an invalid date.

If given a number, it's treated as a time value. So if you're passing a number, make sure it's type number:

 var timeValue = '1461110400000'; console.log( new Date(+timeValue)); 

You could also use Number(timeValue) or parseInt(timeValue) but unary + is less to type.