请问这个判断怎么做，

//初始化变量
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 lookUp(firstName, prop){
// 请把你的代码写在这条注释以下
  for(var i = 0 ; i < contacts.length; i++){
    
    if(contacts[i].firstName == firstName){
      
     for(var j =0; j< contacts[i].likes.length; j++){
       
       if(contacts[i].likes[j] == prop){
         
         return contacts[i].likes[j];
       }else{
         return "No such property";
       }
     }
}else{
  return "No such contact";
}
  }

// 请把你的代码写在这条注释以上
}

// 你可以修改这一行来测试你的代码
lookUp("Akira", "likes");