examplar-processing-of-multidimensional-array.js

// In the exemple, each nested array is a "row", and a set of grades for a student.
const grades = [[89, 77, 78],[76, 82, 81],[91, 94, 89]],
    total = 0,
    average = 0.0;
    
// Columnar approach: get average from student.
for (let row = 0; row < grades.length; row++) {
  for (let col = 0; col < grades[row].length; col++) {
    total += grades[row][col];
  }
  average = total / grades[row].length;
  console.log(`Student ${parseInt(row + 1)} average: ${average.toFixed(2)}.`);
  
  total = 0;
  average = 0.0;
}

// Row-wise approach gives average for each test instead.
for (let col = 0; col = grades.length; col++) {
  for (let row = 0; row = grades[col].length; row++) {
    total += grades[col][row];  
  }
  average = total / grades[row].length;
  console.log(`Test ${parseInt(col + 1)} average: ${average.toFixed(2)}`);
  
  total = 0;
  average = 0.0;
}