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JavaScript JavaScript Basics (Retired) Working With Numbers The Random Challenge

Eric Jusic
Eric Jusic
4,350 Points
Posted by Eric Jusic
Eric Jusic
4,350 Points

Another solution with 2 inputs, what do you say?

Here is my code for randomizing between 2 inputs, which seems to work:

var lowestNumber = parseInt(prompt("Pick lowest number.")); var userInput = parseInt(prompt("Insert number you want to randomize.")); var rollNumber = Math.floor( Math.random() * (userInput - lowestNumber) ) + lowestNumber; var result = "The random number you got is " + rollNumber; alert(result);

If you have any better solution please suggest.

Thank you :)

3 Answers

Steven Parker
Steven Parker
231,271 Points
Steven Parker
Steven Parker
231,271 Points

Two suggestions:

Add 1 to the range to make it inclusive:
"Math.floor(Math.random() * (userInput - lowestNumber + 1 ) ) + lowestNumber"

For clarity, you might want to ask for "highest number" instead of "number you want to randomize."

Eric Jusic
Eric Jusic
4,350 Points
Eric Jusic
Eric Jusic
4,350 Points

Thanks Steven for answering.

Can you clarify why this +1 is there? Is this because of Math.random() can give 0 potentially? Even if it gives 0 + lowestNumber will be the lowestNumber? Or I am missing something?

I agree on the second suggestion, I just named it that way in the workspace.

Steven Parker
Steven Parker
231,271 Points
Steven Parker
Steven Parker
231,271 Points

Remember that Math.random generates values approaching but never equal to 1. So when you multiply it by another value, the product will approach but never equal that number. By adding 1, that allows the range to include the high number in the possible values instead of just generating numbers up to but not including that number.

Eric Jusic
Eric Jusic
4,350 Points
Eric Jusic
Eric Jusic
4,350 Points

Got it now, I forgot on the highest one.

Thank you, Steven, for helping me out again :)