SOURCE

let arr = [
    {
        name: '张三',
        age: 10
    }, {
        name: '李四',
        age: 11
    }
]
for(let i of arr) {
    console.log(i);
    console.log(i.name)
}
console.log('--------------');
for(let j in arr) {
    console.log(j);
    console.log(arr[j].name)
}