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JavaScript

Posted by Benjamin Hedgepeth
Benjamin Hedgepeth
5,672 Points

Isn't the formula slightly wrong?

Shouldn't the expression be 

var number = Math.floor(Math.random() * ((upper - lower) + 1)) + lower;

not

var number = Math.floor(Math.random() * (upper - lower + 1)) + lower;

Without the parentheses around upper and lower the math would violate the order of operations. After all, it is the difference between the range PLUS one. Not (upper - (lower + 1))

2 Answers

Mike Wagner
Mike Wagner
23,888 Points
Mike Wagner
Mike Wagner
23,888 Points

In some ways, you might be right, but since the order of operations only slightly matters in relation to adding and subtracting values, it will still function the same. Personally, I like your more explicit version that defines the upper and lower as a single, related entity. I think it shows a more knowledgeable understanding of what is happening, makes for a cleaner, neater code structure, and makes it easier to refactor or change later down the line, should the need arise.

Tri Pham
Tri Pham
18,671 Points
Tri Pham
Tri Pham
18,671 Points

Adding and Subtraction actually has the same precedence (doesn't matter if you add first or subtract first). If there were multiplication (by something other than 1) instead of adding 1, then yeah you'd be right.