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JavaScript JavaScript Basics (Retired) Working With Numbers Create a random number

Posted by ethan miles
ethan miles
1,970 Points

Why can't we use Math.round instead of Math.floor for the dice roll?

I am working on the create a random number from the java scripts basics course and was wondering why Dave used Math.floor( Math.random() * 6) + 1; instead of Math.round( Math.random() * 6); . it seemed to work fine for me either way just curious if there was a negative to using the latter method, or if it was just to show another method. Thanks in advance for any help!

1 Answer

Steven Parker
Steven Parker
231,268 Points
Steven Parker
Steven Parker
231,268 Points

If you keep "rolling" using your "round" formula, you'll find that you will occasionally roll a "0". The distribution is also not uniform, and the chances of rolling a "0" or a "6" will only be half as likely as rolling one of the other numbers.

By using the "floor" formula, you will get only 1 - 6, and the chances of each number are about even.

ethan miles
ethan miles
1,970 Points

Oh gotcha thanks I appreciate the answer!

brevans26
brevans26
15,198 Points

You are my idol! hahah