javascript - Format date and Subtract days using Moment.js

Question

I would like a variable to hold yesterday's date in the format DD-MM-YYYY using Moment.js. So if today is 15-04-2015, I would like to subtract a day and have 14-4-2015.

I've tried a few combinations like this:

startdate = moment().format('DD-MM-YYYY');
startdate.subtract(1, 'd');

and this:

startdate = moment().format('DD-MM-YYYY').subtract(1, 'd');

and also this:

startdate = moment();
startdate.subtract(1, 'd');
startdate.format('DD-MM-YYYY')

But I'm not getting it...

Answer 1

You have multiple oddities happening. The first has been edited in your post, but it had to do with the order that the methods were being called.

.format returns a string. String does not have a subtract method.

The second issue is that you are subtracting the day, but not actually saving that as a variable.

Your code, then, should look like:

var startdate = moment();
startdate = startdate.subtract(1, "days");
startdate = startdate.format("DD-MM-YYYY");

However, you can chain this together; this would look like:

var startdate = moment().subtract(1, "days").format("DD-MM-YYYY");

The difference is that we're setting startdate to the changes that you're doing on startdate, because moment is destructive.