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JavaScript JavaScript Loops, Arrays and Objects Simplify Repetitive Tasks with Loops What are Loops?

Posted by ammarkhan
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ammarkhan
Front End Web Development Techdegree Student 21,661 Points

understanding RandomNumber function

So, i was trying to understand the code for function in the movie and end up doing this 

function RandomNumber(upper){
    return Math.random(Math.floor(upper) + 1);
}

and it worked. Now i am trying to understand why did this work and why my numbers are in decimals?

1 Answer

Steven Parker
Steven Parker
228,119 Points
Steven Parker
Steven Parker
228,119 Points

:point_right: Math.random doesn't take an argument.

Providing one does not cause an error, but it is ignored. So your function is equavalent to: "Math.random()". And by itself, that returns decimal numbers less than 1.

If you wanted a function to return random integers chosen from a set going from 1 to a specified upper limit, you could write it this way:

function RandomNumber(upper) {
    return Math.floor(Math.random() * upper) + 1;
}