Find the next month of a given date in javascript [duplicate]

Question

I have a piece of code to find the next month of the given date.

var d = new Date('2018-03-31');
dt = new Date(d.setMonth(d.getMonth() + 1));
document.getElementById("demo").innerHTML = dt;

But i'm wondering what is wrong here since it adds one month to March & gives May instead of April?

DEMO:

var d = new Date('2018-03-31');

dt = new Date(d.setMonth(d.getMonth() + 1));
document.getElementById("demo").innerHTML = dt;

<p id="demo"></p>

Answer 1

Use

setMonth(month, day)

d.setMonth(d.getMonth() + 1, 1); where day as 1st day of next month

Only if you are interested in Month part

var d = new Date('2018-03-31');

d.setMonth(d.getMonth() + 1, 1);

dt = new Date(d);
document.getElementById("demo").innerHTML = dt;

<p id="demo"></p>