var ary = [  {    id: 1,    name: "Zhentian"  },  {    id: 2,    name: "Alice"  }];

 

for..in

Print out the props name

for(let person in ary){  console.log(person);  // "0", "1"}

 

for..of

Print out the value

for(let person of ary){  console.log(person); }/*[object Object] {  id: 1,  name: "Zhentian"}[object Object] {  id: 2,  name: "Alice"}*/