Fundamentals

Question 1

What is javascript?

Answer 1

A high-level, Object Oriented, Multi-Paradigm Programming language

Question 2

What is a value?

Answer 2

Piece of data

Question 3

What is a variable?

Answer 3

A named reference to a variable. It is a boxed that we store to values

Question 4

What are the rules of declaring a variable?

Answer 4

1. It is declared with the camelCase notition
2. Variable names can’t start with a number
3. Variable names can only include letters, numbers, _ and $
4. Variable names can’t use reserved keywords.
5. Variable names shouldn’t start with a Capital letter

Question 5

What are the primitive data types?

Answer 5

String, Number, Boolean, undefined, null, symbol and bigint

Question 6

What is a string?

Answer 6

A sequence of characters used to represent text.

Question 7

What is a number

Answer 7

Number is a numeric data type

Question 8

What is a boolean?

Answer 8

A logical data type that can only have true or false as values.

Question 9

What is a undefined data type?

Answer 9

A value that is automatically assigned to a variable that is just been declared.

Question 10

What is a null data type?

Answer 10

a value that represents a reference that points to a nonexistent or invalid object or address.

Question 11

What does Dynamic typing in a language mean?

Answer 11

The data type of the value is automatically defined. The programmer doesn’t need to do this manually.

Question 12

How can you declare a variable?

Answer 12

With the const, let and var keywords.

Question 13

What does reassigning and mutate mean?

Answer 13

Changing the value of the variable.

Question 14

Why should you only use let or const instead of var

Answer 14

Because it will be block scoped and not function scoped

Question 15

What do operators do?

Answer 15

Allows us to transform and/or multiply values

Question 16

What is a syntax?

Answer 16

The structure of statements in a computer language

Question 17

What are some basic math operators

Answer 17

+, -, /, *, **

Question 18

What do assignment operators do?

Answer 18

An assignment operator assigns a value to its left operand based on the value of its right operand.

Question 19

What do comparison operators do?

Answer 19

A comparison operator compares its operands and returns a logical value based on whether the comparison is true.

Question 20

What is operator precedence?

Answer 20

Operator precedence determines how operators are parsed concerning each other. Which operator executes first?

Question 21

What the syntax of template literal?

Answer 21

...

Question 22

How to use multiple lines when using string operators?

Answer 22

with \n\

Question 23

How is the structure of the if else statement called?

Answer 23

control structure.

Question 24

What is type conversion?

Answer 24

Type conversion (or typecasting) means transfer of data from one data type to another.

Question 25

What is type coercion?

Answer 25

Type coercion is the automatic or implicit conversion of values from one data type to another (such as strings to numbers).

Question 26

How can you convert a data type into a number

Answer 26

With the Number() primitive wrapper function.

Question 27

What is the outcome of this syntax: Number('hello')?

Answer 27

NaN (Not a Number)

Question 28

In to which data types can js coerce?

Answer 28

String, Number, Boolean

Question 29

Which operator triggers a number coercion?

Answer 29

the -

Question 30

Which operator triggers a string coercion?

Answer 30

+, /, *

Question 31

What are falsy and truethly values?

Answer 31

They are not false or true, but will be if the are converted into a boolean.

Question 32

What are the falsly values?

Answer 32

0, '', undefined, NaN and Null.

Question 33

What is the difference between a strict logical operator and a loose logical operator?

Answer 33

The strict logical operator (===) does not execute type coercien, which the loose operator (==) does.

Question 34

What does the strict inequity operator do (!==)?

Answer 34

The strict inequality operator (!==) checks whether its two operands are not equal, returning a Boolean result.

Question 35

What are the logical operators?

Answer 35

And (&&), Or (||) & not (!)

Question 36

Is this syntax true or false? | if (12 === 12 && 2 === 1)

Answer 36

false, and operator only returns true if all conditions are true.

Question 37

When doe the OR operator return the value true?

Answer 37

When at least one condition is true.

Question 38

Which logical operator will execute first? &&, ! or ||

Answer 38

!, because the not operator has a higher precedence than the other operators.