I am trying to execute below code:
var a = Math.floor(100000 + Math.random() * 900000); a = a.substring(-2);
I am getting error like
undefined is not a function at line 2, but when I try to do
alert(a), it has something. What is wrong here?
a is a number, not a string. What you probably want to do is something like this:
var val = Math.floor(1000 + Math.random() * 9000); console.log(val);
Math.random()will generate a floating point number in the range [0, 1) (this is not a typo, it is standard mathematical notation to show that 1 is excluded from the range).
- Multiplying by 9000 results in a range of [0, 9000).
- Adding 1000 results in a range of [1000, 10000).
- Flooring chops off the decimal value to give you an integer. Note that it does not round.
If you want to generate an integer in the range [x, y), you can use the following code:
Math.floor(x + (y - x) * Math.random());