Math.Round Javascript

Question

I'm looking for an output of

4.33 = 4.5

4.5517263843648 = 5

Using the Math.round function in javascript. I've tried a few methods but neither seem to work.

Math.round(), Math.floor() and Math.ceil() always round to the nearest, lower and upper integer. In order to round to the nearest integer or half integer you should make a function that does the math. Stack Overflow is not a site to ask for someone else to do it for you. Post what you have tried — R. Schifini, Aug 13 '15 at 12:23
_"you should make a function that does the math"_... How does that help at all? — Cerbrus, Aug 13 '15 at 12:23
just ganna leave this here: `[1,2,1.2,1.8,1.5,1.3].map(function(v){return v + ": " + Math.round(v*2)/2}).join(", ")` — GottZ, Aug 13 '15 at 12:30
@GottZ: Did you get that from the answer on the duplicate link? — Cerbrus, Aug 13 '15 at 12:31
@Cerbrus nope i got it from trying it here: http://chat.stackoverflow.com/transcript/message/25068302#25068302 — GottZ, Aug 13 '15 at 12:36

Rajaprabhu Aravindasamy · Answer 1 · 2015-08-13T12:26:15.487

1

Try to use,

function test(val) {
    var x = Math.floor(val);
    return (val - x) > 0.5 ? Math.ceil(val) : (x + 0.5);
}

DEMO

edited Aug 13 '15 at 12:26

answered Aug 13 '15 at 12:24

This answer doesn't work. `test(0.1)` returns `0.5`, `test(1.1)` returns `1.5`. – Cerbrus Aug 13 '15 at 12:25
@Cerbrus Thats what he asked for. Right? – Rajaprabhu Aravindasamy Aug 13 '15 at 12:26
He wants to round it to the nearest half. – Cerbrus Aug 13 '15 at 12:27
1

@Cerbrus When did you read OP's mind? Don't speculate! Let OP speak up. – Rajaprabhu Aravindasamy Aug 13 '15 at 12:28
Your assumption that the OP always wants to round _up_ to the next `0.5` is just as much of a speculation. Besides, it's uncommon for a rounding function to always round in the same direction. – Cerbrus Aug 13 '15 at 12:29
4

His examples clearly show that he wants the the next 0.5. `4.5517263843648 = 5` – Adrien Neveu Aug 13 '15 at 12:32
@Cerbrus The nearest half of 4.55 is 4.5. The upper half is 5. – Adrien Neveu Aug 13 '15 at 12:33
1

Ugh, I'm blind as a bat. You guys are right. – Cerbrus Aug 13 '15 at 12:33
@Cerbrus Haha, it happens.. – Adrien Neveu Aug 13 '15 at 12:34