CODEWITHSUNDEEP
javascriptarrays
GrumpyCrouton
GrumpyCrouton

Reputation: 8621

Get array key of subarray with the greatest value

I have an array in javascript with this structure:

controllers: Array(2)
    0: Object
        vram: 4095
    1: Object
        vram: 1024

This array is generated via si.graphics. There can be more sub-arrays with different values.

I need to somehow return just the index of the controller with the most vram. I've found other stack questions about something similar, but seemingly only with flat arrays, but this array is multi-dimensional.

I haven't tried much to accomplish this because I simply do not know where to start.

How can I get the index of the sub-array with the most vram?

This is not a duplicate because it is focusing on getting the highest value itself, which is pretty trivial and is not what I am/was asking for.

Upvotes: 1

Views: 67

Answers (4)

colxi
colxi

Reputation: 8670

Simply iterate the controllers Object, and check each vram value, storing always the highest one, would do the trick

let controllers =  [
    {"vram":4095},  // index 0
    {"vram":1024},  // index 1
    {"vram":55555}, // index 2
    {"vram":123}    // index 3...
];

let max = 0;
for(let i in controllers){ 
    if(controllers[i].vram > controllers[max].vram ) max = i
}

console.log(max); // outputs 2

Upvotes: 1

Cory Kleiser
Cory Kleiser

Reputation: 2024

If you are just trying to get the the highest value then the following function in the code snippet will do what you need:

const myArray = [
  {vram: 100},
  {vram: 200},
  {vram: 150}
]

function getHighestVram(array){
  let highestVram = 0;
  for (i in array){
    if(array[i].vram > highestVram) {
      highestVram = array[i].vram;
    }
  }
  return highestVram;
}
    
const maxVram = getHighestVram(myArray);

console.log(maxVram);

If you want to find the index with the highest vram you can use a similar function. Like this:

const myArray = [
  {vram: 100},
  {vram: 200},
  {vram: 150}
]

function getHighestVram(array){
  let highestVram = 0;
  let highestVramIndex;
  for (i in array){
    if(array[i].vram > highestVram) {
      highestVram = array[i].vram;
      highestVramIndex = i;
    }
  }
  return highestVramIndex;
}
    
const maxVramIndex = getHighestVram(myArray);

console.log(maxVramIndex);

Upvotes: 1

Nina Scholz
Nina Scholz

Reputation: 386560

You could reduce the array by checking the value and with the value of the last max value.

var controllers = [{ vram: 4095 }, { vram: 1024 }],
    maxIndex = controllers.reduce(
        (r, { vram }, i, a) => !i || vram > a[r].vram ? i : r,
        undefined
    );

console.log(maxIndex);

Upvotes: 1

Saeed
Saeed

Reputation: 5488

Use something like below

var controllers = {
    0: {
        vram: 4096
    },
    1: {
        vram: 1024
    },
    2: {
        vram: 1024
    }
};

var max = -999999,
  maxKey = -1;


for(var key in controllers) {
  if(controllers[key]['vram'] > max) {
    max = controllers[key]['vram'];
    maxKey = key;
  }
}

console.log(maxKey);
console.log(max);

Upvotes: 1

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