js的foreach遍历

const numbers = [1, 2, 3, 4, 5];

// 使用 forEach 遍历数组并打印每个元素
numbers.forEach(function(number, index) {
  console.log(`Index ${index}: ${number}`);
});

// 使用箭头函数简化代码
numbers.forEach((number, index) => console.log(`Index ${index}: ${number}`));

// 计算数组元素的总和
let sum = 0;
numbers.forEach(number => sum += number);
console.log(`Sum: ${sum}`);

try {
  [1, 2, 3, 4, 5].forEach((number, index) => {
    if (number === 3) throw new Error('Break');
    console.log(number);
  });
} catch (e) {
  if (e.message !== 'Break') throw e;
}

const sparseArray = [1, , 3];
sparseArray.forEach((number, index) => console.log(`Index ${index}: ${number}`));
// 输出:
// Index 0: 1
// Index 2: 3

const obj = {
  value: 10,
  printValue: function() {
    [1, 2, 3].forEach(function(number) {
      console.log(this.value + number); // 非严格模式下，this 指向全局对象
    }, this); // 传递 this 作为第二个参数
  }
};

obj.printValue(); // 输出 11, 12, 13

const obj = {
  value: 10,
  printValue: function() {
    [1, 2, 3].forEach(number => console.log(this.value + number));
  }
};

obj.printValue(); // 输出 11, 12, 13