JavaScript - How to create random longitude and latitudes?

function getRandomInRange(from, to, fixed) {
    return (Math.random() * (to - from) + from).toFixed(fixed) * 1;
    // .toFixed() returns string, so ' * 1' is a trick to convert to number
}

In your case: getRandomInRange(-180, 180, 3):

12.693
-164.602
-7.076
-37.286
52.347
-160.839

Math.random()*360 - 180

that will get you a range of -180 to 180

And if you really only want 3 decimal places

Math.round((Math.random()*360 - 180) * 1000)/1000