//Setup

 var contacts = [

 {

 "firstName": "Akira",

 "lastName": "Laine",

 "number": "0543236543",

 "likes": ["Pizza", "Coding", "Brownie Points"]

 },

 {

 "firstName": "Harry",

 "lastName": "Potter",

 "number": "0994372684",

 "likes": ["Hogwarts", "Magic", "Hagrid"]

 },

 {

 "firstName": "Sherlock",

 "lastName": "Holmes",

 "number": "0487345643",

 "likes": ["Intriguing Cases", "Violin"]

 },

 {

 "firstName": "Kristian",

 "lastName": "Vos",

 "number": "unknown",

 "likes": ["Javascript", "Gaming", "Foxes"]

 }

 ];

 function lookUpProfile(firstName, prop){

 var hasName = false;

 //设置标量hasName，作为firstName判定的结果

 for (var i = 0; i < contacts.length; i++) {

     if (contacts[i].firstName == firstName) {

         hasName = true;

         if (contacts[i].hasOwnProperty(prop)) {

             return contacts[i][prop];

         } else {

             return "No such property";

         }

     }

 }

 if(!hasName){

     //等循环执行完之后再对是否有firstName的判定结果进行处理，避免影响prop属性的判定过程

     return "No such contact";

 }

 }

 lookUpProfile("Akira", "likes");