how to return string from constructor function in javascript?

Question

as you know when we new a Date object it returns an string,

it means when you execute this code

console.log(new Date());

it returns an string like this: Sun Jan 17 2016 16:26:55 GMT+0330 (Iran Standard Time)

i want to do exact the same thing and return an string when somebody new my object...

is it possible?

So you have a constructor, and want to convert the instances to strings? — Ram
– Ram, Commented Jan 17, 2016 at 13:07
@TarunDugar excuse me for my bad English ,,, I mean if my object is Date2 then I want to return an string when someone call new Date2() — Mosijava
– Mosijava, Commented Jan 17, 2016 at 13:23
you cannot do new Date2(). If you want to convert something to string use toString() — Tarun Dugar
– Tarun Dugar, Commented Jan 17, 2016 at 13:24
new Date() does not return a string. It's just the console that formats Date objects as such. — Bergi
– Bergi, Commented May 11, 2016 at 6:00

guysigner · Accepted Answer · 2016-05-11 05:49:35Z

2

It is possible. You can to use Object.prototype.toString (reference in this link):

function MyObject () {
  this.numProperty = 1;
  this.strProperty = "some string";
}
MyObject.prototype.toString = function (){
 return this.strProperty;
}

// example usage:
var obj = new MyObject();
document.getElementById("x").innerHTML = obj;

EDIT: for console.log behavior you can use either

console.log(obj.toString());

or

Console.prototype.logO = function (obj) {
    this.log(obj.toString());
}
// and then
console.logO(obj);

The last line is what you wanted in the first place, but I would go for the first option as it's less wordy.

Here's a JSFiddle.

edited May 11, 2016 at 5:49

answered Jan 17, 2016 at 13:15

guysigner

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1 Comment

Mosijava Over a year ago

thanks for answer but as you can see in your fiddle, it works with innnerHTML() function but it's not working with console.log(). is there any way to makes it work in console.log?

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