为什么调用函数后它的对象属性值为undefined?

Question

var contacts = [    {        "firstName": "Akira",        "lastName": "Laine",        "number": "0543236543",        "likes": ["Pizza", "Coding", "Brownie Points"]    },    {        "firstName": "Harry",        "lastName": "Potter",        "number": "0994372684",        "likes": ["Hogwarts", "Magic", "Hagrid"]    }    ];function lookUp(p){    alert(contacts[0].p);}lookUp("number");上面的函数调用后，显示的结果是 undefined ,为什么不是 "0543236543" ？

Answer 1

alert(contacts[0][p]);