AWS, JavaScript, React - Deploy Web Apps on the Cloud - JavaScript Variables Introduction

The video tutorial explains the concept of variables in JavaScript, highlighting their importance in programming. It provides a basic example of declaring and using variables to store values, demonstrating how to output these values using JavaScript methods. The tutorial also covers variable identifiers, naming rules, and data types, including numbers and strings. An example is given to illustrate changing a numerical value to a text string within variables.

What is the primary purpose of a variable in programming?

• To store a value that can change

• To store a fixed value

• To perform calculations

• To display output

In the example provided, what is the value of variable Z?

• 25

• 15

• 10

• 30

Which of the following is NOT a rule for naming variable identifiers?

• Reserved words cannot be used as names

• Names are case insensitive

• Names must begin with a letter

• Names can contain letters, digits, underscores, and dollar signs

What happens if you put quotes around a number in JavaScript?

• It becomes a variable

• It is treated as a number

• It is treated as a string

• It causes an error

In the example, what is the result when the numerical value 10 is added to the string value '15'?

• 1015

• Error

• 25

• 1510