week 2

Question 1

4 types of JS variables:

Answer 1

Automatically
Using var
Using let
Using const

Question 2

In JavaScript, if a variable is assigned without using a declaration keyword (var, let, or const), the variable will be implicitly declared as a global variable, even if it is inside a function or block. This can lead to unintended consequences

Answer 2

Automatic Variable

Question 3

is limited to the block, statement, or expression where it’s defined. A block is defined by curly braces {}. This makes it safer for use in loops, conditionals, and other block-level structures.

Answer 3

A let variable

Question 4

In JavaScript, it is used to declare variables that cannot be reassigned once they have been initialized. It is very similar to let in terms of scoping (block-scoped) and behavior with hoisting, but it has some unique properties

Answer 4

const

Question 5

Primitive Types

Answer 5

Number: Represents both integers and floating-point numbers.
String: Represents textual data.
Boolean: Represents logical true or false values.
BigInt: Represents integers with arbitrary precision.
Symbol: Represents unique identifiers.
Undefined: A variable that has been declared but not assigned a value.
Null: Represents the intentional absence of any object value.

Question 6

Represents both integers and floating-point numbers.

Answer 6

Number:

Question 7

Represents textual data.

Answer 7

String:

Question 8

Represents logical true or false values.

Answer 8

Boolean:

Question 9

Represents integers with arbitrary precision.

Answer 9

BigInt:

Question 10

Represents unique identifiers.

Answer 10

Symbol:

Question 11

A variable that has been declared but not assigned a value.

Answer 11

Undefined:

Question 12

Represents the intentional absence of any object value.

Answer 12

Null:

Question 13

Non-Primitive (Object) Types:

Answer 13

Object: A collection of properties.
Array: A list-like object.
Function: A callable object that performs a task or computes a value.
Date: A built-in object for handling dates and times.
RegExp: A built-in object for regular expressions.
Error: Represents runtime errors.

Question 14

A collection of properties.

Answer 14

Object:

Question 15

A list-like object.

Answer 15

Array:

Question 16

A callable object that performs a task or computes a value.

Answer 16

Function:

Question 17

A built-in object for handling dates and times.

Answer 17

Date:

Question 18

A built-in object for regular expressions.

Answer 18

RegExp:

Question 19

Represents runtime errors

Answer 19

Error:

Question 20

All JavaScript variables must be identified with unique names, these unique names are called

Answer 20

identifiers

Question 21

can be short names (like x and y) or more descriptive names (age, sum, totalVolume).

Answer 21

Identifiers

Question 22

can be short names (like x and y) or more descriptive names (age, sum, totalVolume).

Answer 22

Identifiers

Question 23

When you use—- to declare a variable in JavaScript, you are explicitly defining that variable within a particular scope. Variables declared with—-are function-scoped, meaning they are accessible within the function they are declared in, or globally if declared outside of any function. This is in contrast to assigning a value to a variable without declaring it, which can lead to implicit global variables and unintended side effects.

Answer 23

var