JavaScript variables

Question 1

General rules for naming variables

Answer 1

• cannot start with numbers
• case sensitive
• cannot be the same as keywords

Question 2

What is a variable

Answer 2

It is a container for a value.

- It holds reusable data in a program and associates it with a name

Question 3

var

Answer 3

a key word that declares new variable
var myName = 'Bethani';
console.log(myName);
// Output: Bethani 

In this case, key word variable is being used.

• var is declaring the variable myName
• Bethani is the value being assigned to myName
• After the variable is declared, the string value ‘Bethani’ is printed to the console.

Question 4

Where are variables stored

Answer 4

In memory

Question 5

Preferred variable keywords

Answer 5

let is the preferred way to declare a variable for reassigning and const when you want it to remain constant

Question 6

When variables have not been initialized

Answer 6

they store the primitive data type undefined.

Question 7

Mathematical assignment operators and variables

Answer 7

make it easy to calculate a new value and assign it to the same variable

Question 8

+ operator used for what in variables

Answer 8

used to concatenate strings held in variables

Question 9

Since ES6 what are backticks ` and ${} used for

Answer 9

` backticks
${} placeholder
- used to interpolate values into a string.

Question 10

typeof keyword

Answer 10

returns the data type (as a string) of a value