Javascript Lists Lecture Knowledge Check

Which of the following is TRUE about lists.

• They can't change size

• They can only hold numbers

• The order of items is not kept

• Lists can be stored in a variable

In a list each item is assigned a number in that list. That number is called the ________?

• location

• index

• identifier

• list code

given the list

var names = ["Ann", "Bob", "Chuck", "Dana"];

which name is at names[2]?

• Ann

• Bob

• Chuck

• Dana

given

var nums = [3, 4, 6, 2, 9, 1];

what is

nums[1] + nums[3]

• 4

• 5

• 6

• 9

given the list

var names = ["Ann", "Bob", "Chuck", "Dana"];

how would I replace "Bob" with "Bill"?

• names["Bob"] = "Bill";

• list[1] = "Bill";

• names[1] = "Bill";

• names[2] = "Bill";

What would be the output of the following code?

var myList = ["A", "B", "C"];

console.log(myList.length);

• 2

• 3

• 4

If I had a list in my program called todo. While running lots of items are added to the end of the list. How can I get the last item in the list.

• todo[last]

• todo[todo.length]

• todo.length - 1

• todo[todo.length - 1]

what is in myNumbers after the following code runs.

var myNumbers = [10,20,25];

myNumbers[0] = 5;

myNumbers[2] = 30;

• [10,20,25]

• [5,20,25]

• [5,20,30]

• [5,10,20,25,30]

var myStuff = [20, “hat”, “pow”, 5];      
myStuff[1] = “cat”;                                  
myStuff[2] = myStuff[1];                       
myStuff[0] = myStuff[3] + 10;              
myStuff[3] = myStuff[0] + myStuff[0];

• ["cat10", “hat”, “cat10cat10”, 5]

• [15, “cat”, “hat”, 40]

• [15, “cat”, “cat”, 30]

• [15, “hat”, “pow”, 30]

var i = 1;

var nums = [3,2,1,5];

var x = (nums[ i + 1]) + (nums[i] + 1);

What is the value of x?

(a)