我们有一个对象数组，里面存储着通讯录。

函数lookUp有两个预定义参数：firstName值和prop属性 。

函数将会检查通讯录中是否存在一个与传入的firstName相同的联系人。如果存在，那么还需要检查对应的联系人中是否存在prop属性。

如果它们都存在，函数返回prop属性对应的值。

如果firstName值不存在，返回"No such contact"。

如果prop属性不存在，返回"No such property"。

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(name, prop) {  for (var i = 0; i < contacts.length; i++) {    if (name == contacts[i]["firstName"]) {      if (contacts[i].hasOwnProperty(prop)) {        return contacts[i][prop];      }else{        return "No such property";      }    }  }  return "No such contact";}lookUpProfile("Akira", "likes");//["Pizza", "Coding", "Brownie Points"]