Calculate vector with given angle and length

I just wanted to point out, that the answers of are not correct IMHO. I've created a JSFiddle showing that the correct implementation must be something like this:

function getRelativeVector(angle, length, xOffset, yOffset) {
    angle = angle * Math.PI / 180; 
    return { 
        X:length * Math.sin(angle) + xOffset, 
        Y:length * Math.cos(angle) + yOffset 
    };
}

The other solutions shown here from @Audrius and @Markus are simply twisted in cos and sin. They are working for angles between 0 and 45 degrees only.

The formula would be:

• X = length * sin(angle) + xLocation
• Y = length * cos(angle) + yLocation

This function returns an array [xCoord, yCoord] of the new coordinates:

function myFunction(xCoord, yCoord, angle, length) {
    length = typeof length !== 'undefined' ? length : 10;
    angle = angle * Math.PI / 180; // if you're using degrees instead of radians
    return [length * Math.cos(angle) + xCoord, length * Math.sin(angle) + yCoord]
}