TypeError: contacts[i] is undefined

var bob = { 
	firstName: "Bob", lastName: "Jones", 
	phoneNumber: "(650) 777-7777", 
	email: "bob.jones@example.com" 
}; 

var mary = { 
	firstName: "Mary", 
	lastName: "Johnson", 
	phoneNumber: "(650) 888-8888", 
	email: "mary.johnson@example.com" 
}; 
var contacts = [bob, mary]; 

var list = function(){ 
	for (var i = 0; i < contacts.length; i++) { 
		console.log(contacts[i]); 
	} 
} 

function search(lastName){ 
	for(var i = 0; i < contacts.length; i++){ 
		if(contacts[i].lastName === lastName){ 
			console.log("Bob Jones"); 
		} 
	}
} 
function add(firstname, lastname,  phonenumber, eMail){ 
	newEntry = { 
		firstName: firstname, 
		lastName: lastname, 
		phoneNumber: phonenumber, 
		email: eMail 
	}; 
	contacts.push(newEntry); 
} 
console.log(add("Anu", "Oluwapo", "12355555", "alaja@eko.cc")); 
console.log(list());

//give this output

>Object { firstName: "Bob", lastName: "Jones", phoneNumber: "(650) 777-7777", email: "bob.jones@example.com" }
>Object { firstName: "Mary", lastName: "Johnson", phoneNumber: "(650) 888-8888", email: "mary.johnson@example.com" }
>undefined