const date = new Date();
date.setDate(date.getDate() - 30);
console.log(date); // 2018-03-03T23:10:24.063Z
console.log(date + 'hello'); // Sat Mar 03 2018 15:10:59 GMT-0800 (PST)helloWhat's going on here? How can I use the date value without formatting it to be human readable? Thanks!
2018-03-03T23:10:24.063Z
This is date.toISOString(), so date.toISOString() + 'hello'.
console.log on a Date object is not defined by any spec whatsoever, and thus varies across implementations. (In the first log statement, you are logging a Date. In the second one, you're logging a String)
toString and toISOString is being made. Switch in console.log() perhapstoJSON() is your friend (more often than not):
const date = new Date();
date.setDate(date.getDate() - 30);
console.log(date);
console.log(date.toString());
console.log(`${date.toJSON()}hello`);Internally, Date.prototype.toJSON() uses Date.prototype.toISOString().
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toJSON
When concatenating a date object with a string, internally Date.prototype.toString() is being called - and that creates the output you do not want in your case.
The
Dateobject overrides thetoString()method of theObjectobject; it does not inheritObject.prototype.toString(). ForDateobjects, thetoString()method returns astringrepresentation of the object.The
toString()method always returns astringrepresentation of the date in American English.JavaScript calls the
toString()method automatically when adateis to be represented as a text value or when a date is referred to in a string concatenation.https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date/toString
console.log with the output of toJSON, or that says console.log should call .toString() or .toISOString() on a Date object. I've requested it here: github.com/whatwg/console/issues/132
.toISOString() and when concating a string which includes a date toString() is called is that correct?