let a={
    name:'wq',
    age:22,
    id:9527,
}
let b=['wq',22,9527]
for (item in b){
    console.log(item)
}
for (item of b){
    console.log(item)
}
for (item in a){
    console.log(item)
}
for (item of a){
    console.log(item)
}

console 命令行工具 X clear

console