maxDiff.js

const array = [4, 2, 1, 5];


const maxDiff = array => {
  let result = 0;
  
  for(let i = 0; i < array.length; i++) {
    for(let j = i+1; j < array.length; j++) {
      if(array[i] < array[j] && i < j) {
        result = array[j] - array[i]
      }
    }
  }
  
  return result;
}