下面的list
函数应该列出我的contacts
数组中的人员姓名。为什么这个函数打印'undefined'?
var bob = {
firstName: "Bob",
lastName: "Jones",
phoneNumber: "(650) 777-7777",
email: "[email protected]"
};
var mary = {
firstName: "Mary",
lastName: "Johnson",
phoneNumber: "(650) 888-8888",
email: "[email protected]"
};
var contacts = [bob, mary];
function printPerson(person) {
console.log(person.firstName + " " + person.lastName);
}
var list = function() {
var contactsLength = contacts.length;
for (var i = 0; i < contactsLength; i++) {
console.log(printPerson(contacts[i]));
}
};
list;
然而,而不只是打印出鲍勃·琼斯和玛丽·约翰逊,我得到:
Bob Jones
undefined
Mary Johnson
undefined
有人能解释这是为什么?