如何在JavaScript中遍历初始项目？

const arr = [1, 2, 3, 4, 5];
for (let i = 0; i < arr.length; i++) {
  console.log(arr[i]);
}

const arr = [1, 2, 3, 4, 5];
arr.forEach((item) => {
  console.log(item);
});

const obj = { a: 1, b: 2, c: 3 };
for (let key in obj) {
  console.log(obj[key]);
}

const str = "Hello";
for (let char of str) {
  console.log(char);
}

const arr = [1, 2, 3, 4, 5];
const doubledArr = arr.map((item) => item * 2);
console.log(doubledArr);