Smallest number in array and its position

Question

What I am trying to achieve is to find smallest number in array and its initial position. Here's an example what it should do:

temp = new Array();
temp[0] = 43;
temp[1] = 3;
temp[2] = 23;

So in the end I should know number 3 and position 1. I also had a look here: Obtain smallest value from array in Javascript?, but this way does not give me a number position in the array. Any tips, or code snippets are appreciated.

Oh my god. I just realized that I could use indexOf to find position of the smallest number. — Ed T., Mar 16 '13 at 22:08

score 15 · Accepted Answer · answered Mar 16 '13 at 22:09

Just loop through the array and look for the lowest number:

var index = 0;
var value = temp[0];
for (var i = 1; i < temp.length; i++) {
  if (temp[i] < value) {
    value = temp[i];
    index = i;
  }
}

Now value contains the lowest value, and index contains the lowest index where there is such a value in the array.

score 7 · Answer 2 · answered Mar 16 '13 at 22:09

You want to use indexOf

http://www.w3schools.com/jsref/jsref_indexof_array.asp

Using the code that you had before, from the other question:

temp = new Array();
temp[0] = 43;
temp[1] = 3;
temp[2] = 23;

Array.min = function( array ){
    return Math.min.apply( Math, array );
};

var value = temp.min;
var key = temp.indexOf(value);

score 7 · Answer 3 · edited Jun 07 '17 at 16:56

7

One-liner:

alist=[5,6,3,8,2]

idx=alist.indexOf(Math.min.apply(null,alist))

edited Jun 07 '17 at 16:56

Bugs

4,456
9
32
40

answered Jun 07 '17 at 16:54

Tony

113
1
3

2

Please don't just post code, explain what the code does. – Patrick Hund Jun 07 '17 at 18:25

score 2 · Answer 4 · answered May 28 '21 at 13:34

2

Find the smallest value using Math.min and the spread operator:

var minimumValue = Math.min(...temp);

Then find the index using indexOf:

var minimumValueIndex = temp.indexOf(minimumValue);

I personally prefer the spread operator over apply.

answered May 28 '21 at 13:34

sporklpony

369
4
15

score 1 · Answer 5 · edited Nov 11 '17 at 07:49

1

See this answer of "find max" version of this question. It is simple and good. You can use the index to get the element afterward.

edited Nov 11 '17 at 07:49

Vasyl Lyashkevych

1,734
2
21
35

answered Nov 11 '17 at 06:39

Raku Zeta

21
4

score 1 · Answer 6 · edited May 26 '21 at 14:39

1

You could use reduce, and compare against Infinity.

let minIndex = -1;
arr.reduce((acc, curr, index) => {
    if (curr < acc) {
        minIndex = index;
        return curr;
    } else {
        return acc;
    }
}, Infinity);

edited May 26 '21 at 14:39

ruohola

19,113
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answered Oct 19 '20 at 18:26

Apollo

1,734
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26

score 0 · Answer 7 · answered Oct 02 '19 at 21:55

Here is a solution using simple recursion. The output is an object containing the index position of the min number and the min number itself

const findMinIndex = (arr, min, minIndex, i) => {
  if (arr.length === i) return {minIndex, min};
  if (arr[i] < min) {
    min = arr[i]
    minIndex = i;
  }
  return findMinIndex(arr, min, minIndex, ++i)

}

const arr = [5, 5, 22, 11, 6, 7, 9, 22];
const minIndex = findMinIndex(arr, arr[0], 0, 0)
console.log(minIndex);

Smallest number in array and its position

7 Answers7

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