JavaScript: How to get min number

Question

How can I get the minimum value from an array in JavaScript? I did try the Math.min method and it seems that it doesn't work as expected.

As an example, I have four divs with numeric values:

HTML:

<div id="r">3121</div>
<div id="g">2334</div>
<div id="b">3445</div>
<div id="a">4121</div>

JavaScript:

var r = $('#r').text(),
    g = $('#g').text(),
    b = $('#b').text(),
    p = $('#a').text();

var mainBox = [r,g,b,a];
var minN = Math.min(mainBox);
alert(minN);

Can you please tell me what am I doing wrong?

http://stackoverflow.com/questions/1669190/javascript-min-max-array-values/1669222#1669222 — Popnoodles, Jun 14 '14 at 14:35
This question isn't very good. Should read the documentation. — Evan Trimboli, Jun 14 '14 at 14:37
**Before you answer with this** `var minN = Math.min.apply(Math, mainBox);` - **please check it works because it doesn't** http://jsfiddle.net/V9Bwv/1/ — Popnoodles, Jun 14 '14 at 14:39
@Popnoodles It will when the variables match: http://jsfiddle.net/V9Bwv/2/. :) The last variable was `p`, so it was pulling in an auto-global of the `
` itself with `a`. — Jonathan Lonowski, Jun 14 '14 at 14:42

John Skoumbourdis · Answer 1 · 2014-06-14T14:52:42.220

4

Update answer: This solution is now working

You have to do it with parseInt(..., 10).
The Math.min doesn't accept arrays.

So in your case you will have something like this:

function getMinFromArray (array_of_values) {
    return array_of_values.sort()[0];   
};

var r = parseInt($('#r').text(), 10),
    g = parseInt($('#g').text(), 10),
    b = parseInt($('#b').text(), 10),
    p = parseInt($('#a').text(), 10);

var mainBox = [r,g,b,a];
var result = getMinFromArray(mainBox);

alert(result);

This is a working example: http://jsfiddle.net/CJfWu/2/

edited Jun 14 '14 at 14:52

answered Jun 14 '14 at 14:31

John Skoumbourdis

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...because `text()` returns a string. – Popnoodles Jun 14 '14 at 14:32
1

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/min `min` doesn't accept an array. – Evan Trimboli Jun 14 '14 at 14:33
I didn't downvote (better to comment), that gives NaN. http://jsfiddle.net/V9Bwv/ – Popnoodles Jun 14 '14 at 14:33
Removed -1. Now it's just the same as all the others. – Evan Trimboli Jun 14 '14 at 14:36

score 2 · Answer 2 · answered Jun 14 '14 at 14:35

2

I don't think you can pass an array to Math.min() like that.

Try it like this:

var minValue = Math.min.apply(Math, mainBox);

Or just use it like this:

var minValue = Math.min(r,g,b,p);

answered Jun 14 '14 at 14:35

nl-x

11,762
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Pratik Joshi · Accepted Answer · 2014-06-16T11:33:35.577

1

Working fiddle fiddle

Use following code

//parseInt to convert String => Int.
var    r = parseInt($('#r').text(),10);
var    g = parseInt($('#g').text(),10);
var    b = parseInt($('#b').text(),10);
var    p = parseInt($('#a').text(),10);

//Here sort the values
var minN = Math.min(r,g,b,p);
alert(minN);

edited Jun 16 '14 at 11:33

answered Jun 14 '14 at 14:37

Pratik Joshi

11,485
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@Popnoodles ,Ok you can comment it out, no problem. – Pratik Joshi Jun 14 '14 at 14:41
1

You should always pass the 10 radix to `parseInt` e.g. `parseInt(text, 10)`, otherwise it will parse numbers with leading 0's as octal etc! :) – iCollect.it Ltd Jun 16 '14 at 11:30

score 0 · Answer 4 · answered Jun 14 '14 at 14:39

Try this:

var r = parseInt($('#r').text(), 10),
    g = parseInt($('#g').text(), 10),
    b = parseInt($('#b').text(), 10),
    p = parseInt($('#a').text(), 10);

var minN=Math.min(r,g,b,p);
alert(minN);

As .min() does not accept array argument rather just comma separated integers, so you would place your integers one by one and it will return the minimum value.

score 0 · Answer 5 · answered Jun 14 '14 at 14:49

0

You may try this:

var vals = [];
$('#r, #g, #b, #a').each(function(i){
    vals[i] = $(this).text();
});
var min = Math.min.apply(Math, vals);

answered Jun 14 '14 at 14:49

The Alpha

143,660
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score 0 · Answer 6 · answered Jun 14 '14 at 15:24

I prefer to use a general solution for any number of divs that contain numbers. First, add a class for those divs with numbers as their text. For example, class="items". Then use the following function to get the minimum values

var getMinValueForDivs = function (divsClass) {
    var itemDivs = $('.' + divsClass);
    var values = [];
    itemDivs.each(function (index, item) {
        values.push(item.innerHTML);
    });

    return Math.min.apply(this, values);
}

Ex:

$(document).ready(function () { 
    getMinValueForDivs('items'); 
});

JavaScript: How to get min number

6 Answers6