CODEWITHSUNDEEP
javascriptmethodsreturn
ion
ion

Reputation: 79

Strange method result using Math.round

When this method is called with knownScore = 70, newScore = 70, depth = 1, it returns 3535 !!!!! How is this possible?

this.weightedAvg = function(depth, knownScore, newScore) {
   if ((knownScore > 100) || (knownScore < -100)) return newScore;
   else return Math.round((depth*knownScore + newScore)/(depth + 1));
};

When called with values 35, 70, 2, it returns 2357! Any help please?

Upvotes: 1

Views: 57

Answers (2)

Shryme
Shryme

Reputation: 1570

You need to parse your var to number like this:

var number1 = Number(n);

You are passing string so he do "2" + "35" + "70" instead of 2 + 35 + 70 !

Upvotes: 2

Tibos
Tibos

Reputation: 27823

The value of newScore you're passing to the function is a string. You should make sure they are all numbers. This code will work (notice the + sign that converts newScore to a number):

this.weightedAvg = function(depth, knownScore, newScore) {
    if ((knownScore > 100) || (knownScore < -100)) return newScore;
    else return Math.round((depth*knownScore + +newScore)/(depth + 1));
};

More details:

70 + '70' // this is string concatenation instead of addition, results in 7070

The result is converted to a number when it is divided by 2:

'7070'/2 // converts to number, resulting in 3535

Upvotes: 3

Related Questions