JAVASCRIPT

2nd highest number from array

var arr = [1,2, -3, 15, 77, 12, 55];
var highest = 0, secondHighest = 0;
// OR var highest = arr[0], secondHighest = arr[0];

for(var i=0; i<arr.length; i++){
  if(arr[i] > highest){
    secondHighest = highest;
    highest = arr[i]; 
  }

  if(arr[i] < highest && arr[i] > secondHighest){
    secondHighest = arr[i];
  }
}

console.log('>> highest number : ',highest); // 77
console.log('>> secondHighest number : ',secondHighest); // 55

2nd highest number from array

 static int secondHighest(int... nums) {
    int high1 = Integer.MIN_VALUE;
    int high2 = Integer.MIN_VALUE;
    for (int num : nums) {
      if (num > high1) {
        high2 = high1;
        high1 = num;
      } else if (num > high2) {
        high2 = num;
      }
    }
    return high2;
 }