js 遍历循环foreach

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

// 使用 forEach 打印每个数字
numbers.forEach(function(currentValue, index, array) {
  console.log(`Index ${index}: ${currentValue}`);
});

// 使用 forEach 计算所有数字的和
let sum = 0;
numbers.forEach(function(value) {
  sum += value;
});
console.log(`Sum of all numbers: ${sum}`);

// 使用 forEach 修改数组元素
const updatedNumbers = [];
numbers.forEach(function(value) {
  updatedNumbers.push(value * 2);
});
console.log(`Updated numbers: ${updatedNumbers}`);

for (let i = 0; i < numbers.length; i++) {
  if (numbers[i] > 3) break;
  console.log(numbers[i]);
}

const obj = {
  value: 10,
  printValues: function() {
    numbers.forEach(function(number) {
      console.log(this.value + number);
    }, this); // 手动绑定 this
  }
};

obj.printValues();

printValues: function() {
  numbers.forEach((number) => {
    console.log(this.value + number);
  });
}