Javascript Variables

Question 1

Question

Which of these variables are not valid in Javascript?

Answer

4_colors
Color
color
$color

Question 2

Question

What happens when you declare a variable like var myVar;

Answer

The variable value(output) is set to undefined
The variable value(output) is set to null

Question 3

Question

What are some of the main differences between null and undefined?

Answer

Null is used to tell the program that a value is truly empty
Unlike undefined, null is a falsy value
typeof null will return "Object" and typeof undefined returns "undefined"

Question 4

Question

=== operator is less strict in terms of identifying equality than ==

Answer

True
False

Question 5

Question

Variables created inside of a function can only be used within the function

Answer

True
False

Question 6

Question

Which var world is considered to have a global scope?

Answer

var date; function sayHello(){ }
function sayHello(){ var date; }

Question 7

Question

What will console log out in the following code? var part1 = "Team "; function bam() { var part2 = "Treehouse"; console.log(part2); } bam();

Answer

Treehouse
Undefined
Team

Question 8

Question

Declaring a variable without a var keyword will evaluate the variable with global scope

Answer

True
False

Next up

Javascript Variables

Description

Resource summary

Question 1

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Similar

	Created by Rene Escobar over 9 years ago