var data = ["dog", "pig", "cat"];

// 1、遍历下标索引
for (let index in data) {
    console.log(index + "->" + data[index]);
}
/**
0->dog
1->pig
2->cat
*/


// 2、遍历值
for (let value of data) {
    console.log(value);
}
/**
dog
pig
cat
*/

var data = {
    name: "Tom",
    age: 23
};


// 1、遍历key
for(let key in data){
    console.log(key);
}
/**
name
age
*/


// 2、遍历对象键值对
for(let [key, value] of Object.entries(data)){
    console.log(key + "->" + value);
}
/**
name->Tom
age->23
*/


// 3、遍历对象键
for(let key of Object.keys(data)){
    console.log(key);
}
/**
name
age
*/


// 4、遍历对象值
for(let value of Object.values(data)){
    console.log(value);
}
/**
Tom
23
*/