Finding lowest value of an array of objects

Question

I am making a game with obstacles currently and I want to find the object with the lowest X value. Here is an example of an array.

var array = [{x:500, y:400}, {x:80, y:400}, {x:900, y:400}];

I want to be able to determine what is the lowest X in this group(80) and return it to me. Is there any way to do this?

Use a sort, and then pick the first/last depending on the order of your sort. — evolutionxbox, Nov 17 '21 at 12:13
Does this answer your question? [Sort array of objects by string property value](https://stackoverflow.com/questions/1129216/sort-array-of-objects-by-string-property-value) — evolutionxbox, Nov 17 '21 at 12:13
Check this out: `array.sort(({ x: x1 }, { x: x2 }) => x1 - x2)[0]` // {x: 80, y: 400} — A1exandr Belan, Nov 17 '21 at 12:29

Ramesh Reddy · Accepted Answer · 2021-11-17T12:52:37.563

4

You don't need to sort the array or use an external library. You can use Array.prototype.reduce to find the object with minimum x in linear time:

const array = [{x:500, y:400}, {x:80, y:400}, {x:900, y:400}];
const minX = array.reduce((acc, curr) => curr.x < acc.x ? curr : acc, array[0] || undefined);
console.log(minX)

edited Nov 17 '21 at 12:52

answered Nov 17 '21 at 12:21

Ramesh Reddy

10,159
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1

I prefer this to sorting – evolutionxbox Nov 17 '21 at 12:28
1

Just beware of empty array, becouse of exeption: 'Reduce of empty array with no initial value' – A1exandr Belan Nov 17 '21 at 12:38
1

@FFire Yes. Updated to not throw an error when empty array is used – Ramesh Reddy Nov 17 '21 at 12:53

score 0 · Answer 2 · edited Nov 17 '21 at 12:21

0

You can use lodash

var array = [{
  x: 500,
  y: 400
}, {
  x: 80,
  y: 400
}, {
  x: 900,
  y: 400
}];
console.log(_.minBy(array, 'x'))

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.21/lodash.min.js"></script>

edited Nov 17 '21 at 12:21

Not A Bot

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answered Nov 17 '21 at 12:16

Hyperella

60
4

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May you also suggest non-library solution? Since lodash has not been used nor asked for? – evolutionxbox Nov 17 '21 at 12:17

score 0 · Answer 3 · answered Nov 17 '21 at 12:19

0

let min = Infinity
for (var i=0; i<array.length; i++){
    if (array[i].x<min) min = array[i].x
}

Here min is your answer. There might be easier way to do this, but his gets the job done.

answered Nov 17 '21 at 12:19

Sudwipto Kumar Mondal

1

score 0 · Answer 4 · edited Nov 17 '21 at 13:01

0

sort and get the first

var arr = [{
  x: 500,
  y: 400
}, {
  x: 80,
  y: 400
}, {
  x: 900,
  y: 400
}];
arr.sort((a, b) => a.x < b.x ? -1 : (a.x > b.x ? 1 : 0));
console.log(arr[0]);

edited Nov 17 '21 at 13:01

Not A Bot

2,474
2
16
33

answered Nov 17 '21 at 12:28

Soshiv Upreti

101
1
6

Actually you don't need ternary operators, just subtraction – A1exandr Belan Nov 17 '21 at 12:31

Finding lowest value of an array of objects

4 Answers4