Return Index of Highest Value in an Array

Return index of greatest value in an array

This is probably the best way, since it’s reliable and works on old browsers:

function indexOfMax(arr) {
    if (arr.length === 0) {
        return -1;
    }

    var max = arr[0];
    var maxIndex = 0;

    for (var i = 1; i < arr.length; i++) {
        if (arr[i] > max) {
            maxIndex = i;
            max = arr[i];
        }
    }

    return maxIndex;
}

There’s also this one-liner:

let i = arr.indexOf(Math.max(...arr));

It performs twice as many comparisons as necessary and will throw a RangeError on large arrays, though. I’d stick to the function.

Javascript return all indexes of highest values in an array

Using Math.max you can get the maximum element. Post that you map over the array and get the indices of this max element. The complexity of this approach is O(n);

const arr = [0,1,4,3,4];

const max = Math.max(...arr);

const res = [];

arr.forEach((item, index) => item === max ? res.push(index): null);

console.log(res);

How to find array index of largest value?

public int getIndexOfLargest( int[] array )
{
  if ( array == null || array.length == 0 ) return -1; // null or empty

  int largest = 0;
  for ( int i = 1; i < array.length; i++ )
  {
      if ( array[i] > array[largest] ) largest = i;
  }
  return largest; // position of the first largest found
}

how can I get the index of the max value in an array?

If you do not want to use another class you can do the below.
You need to store both the max and the index of where max was so that you can also print the city

String[] city = getCities ();  // assuming this code is done
int[] temp = getTemparatures ();
int max = Integer.MIN_VALUE;
int index = -1;

for(int i = 0; i < temp.length; i ++){
    if(max < temp[i]){
        max = temp[i];
        index = i;
    }
}

System.out.println ("The city with the highest average temperature is " + city[index] + 
" with an average temperature of " + temp[index]);