使用循环键计算对象值

const students = {
  Alice: { math: 90, science: 85 },
  Bob: { math: 88, science: 92 },
  Charlie: { math: 78, science: 88 }
};

let totalScore = 0;
let studentCount = 0;

for (const [name, scores] of Object.entries(students)) {
  totalScore += scores.math + scores.science;
  studentCount++;
}

const averageScore = totalScore / (studentCount * 2); // 每个学生有两个科目

console.log(`Total Score: ${totalScore}`);
console.log(`Average Score: ${averageScore}`);

for (const [name, scores] of Object.entries(students)) {
  totalScore += Number(scores.math) + Number(scores.science);
  studentCount++;
}

for (const [name, scores] of Object.entries(students)) {
  totalScore += (scores.math || 0) + (scores.science || 0);
  studentCount++;
}