School Grades JSFundamentals

function schoolGrades(arr) {
  let grades = {};

  // Parse input and update grades object
  for (let line of arr) {
    let tokens = line.split(' ');
    let name = tokens.shift();
    let studentGrades = tokens.map(x => Number(x));

    if (name in grades) {
      for (let i = 0; i < studentGrades.length; i++) {
        grades[name].push(studentGrades[i]);
      }
    } else {
      grades[name] = studentGrades;
    }
  }

  let averages = {};

  // Calculate average grade for each student and store in averages object
  for (let name in grades) {
    let total = 0;
    for (let i = 0; i < grades[name].length; i++) {
      total += grades[name][i];
    }
    let average = (total / grades[name].length).toFixed(2);
    averages[name] = average;
  }

  // Sort averages object by student name and print the results
  let sortedAverages = Object.entries(averages).sort((a, b) => a[0].localeCompare(b[0]));
  for (let [name, grade] of sortedAverages) {
    console.log(`${name}: ${grade}`);
  }
}

OR

function schoolGrades(arr) {
  let grades = {};

  // Parse input and update grades object
  for (let line of arr) {
    let tokens = line.split(' ');
    let name = tokens.shift();
    let studentGrades = tokens.map(x => Number(x));

    if (name in grades) {
      grades[name].push(...studentGrades);
    } else {
      grades[name] = studentGrades;
    }
  }

  let averages = {};

  // Calculate average grade for each student and store in averages object
  for (let name in grades) {
    let total = grades[name].reduce((acc, curr) => acc + curr);
    let average = (total / grades[name].length).toFixed(2);
    averages[name] = average;
  }

  // Sort averages object by student name and print the results
  let sortedAverages = Object.entries(averages).sort((a, b) => a[0].localeCompare(b[0]));
  for (let [name, grade] of sortedAverages) {
    console.log(`${name}: ${grade}`);
  }
}