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5,791 Points# Generating random number between x and y or generating random number from x to y ?

Mr Dave said to generate random number between x and y, but why the solution include x and y? If it were between shouldn't it excludes x and y, or in other words :

x < random number < y

So the formula should be this..

Math.floor ( Math.random * ( y - x - 1 ) )+ ( x + 1 );

if He uses the formula written in the random.js workspace, it means generating random number from x to y or in other words, x <=random number <= y

Please correct me if I am wrong....

## 2 Answers

###### Steven Parker

225,712 Points## Programming terms sometimes vary from mathematical ones.

From a mathematical perspective you're totally right, the word "between" would mean exclusive of the end points. But in programming "between" can be either exclusive or inclusive; and when not explicitly specified, it's most likely to mean inclusive. In SQL it is an operator keyword, and it is __always__ inclusive.

In the case of the video, the formula shown is inclusive just as you described.

*If you think "between" is confusing, in programming a "variable" can be a "constant".*

###### arik

5,791 PointsThank you very much indeed for the answer. I get the point now. If it's not specified it means inclusive.