Manipulating Data with Expressions

Question 1

What is an expression?

Answer 1

An expression is any code that resolves to a single value.

Question 2

Is a string such as ‘hello’ or a number such as 10 considered an expression and why?

Answer 2

the string ‘hello’ and the number ‘10’ are both considered expressions because they are both a single value.

Question 3

What is an easy way of remembering what an Expression?

Answer 3

“If it produces a value, it’s an expression.”

Question 4

What do you use in order to perform mathematical calculations within a code?

Answer 4

To perform mathematical calculations within our code, we can use operators.

Question 5

What is the symbol for the addition operator?

Answer 5

+

Question 6

What is the symbol for the subtraction operator?

Answer 6

-

Question 7

What is the symbol for the multiplication operator?

Answer 7

*

Question 8

What is the symbol for the division operator?

Answer 8

/

Question 9

What is using operators in order to calculate a result an example of?

Answer 9

Using operators in order to calculate a result is an example of Evaluation.

Question 10

What is Evaluation?

Answer 10

Evaluation is the process of determining the value of an expression or statement in your code.

Question 11

What is an Operand?

Answer 11

An Operand is a piece of data used by an Operator.

Question 12

In the expression - 4 * 25, which are the first and second operands?

Answer 12

4 is the first operand and 25 is the second operand.

Question 13

What is a Modulo Operator in JavaScript?

Answer 13

The Modulo Operator divides the first operand by the second operand and then evaluates it to a number showing the remainder.

Question 14

What is the symbol for the Modulo Operator in JS?

Answer 14

The % symbol is used for the Modulo Operator in JS.

Question 15

Which operator is great for finding out whether numbers are even or odd?

Answer 15

The Modulo Operator is a great operator to find out whether numbers are even or odd.

Question 16

Using the Modulo Operator, how can you find out whether a number is even or odd?

Answer 16

Even numbers will produce a remainder of 0 when divided by 2 and Odd numbers will produce a remainder of 1 when divided by 2.

Question 17

What is the symbol for Exponentiation?

Answer 17

The Exponentiation Symbol is **

Question 18

What does The Exponentiation Operator do?

Answer 18

The Exponentiation Operator Multiplies the First Operand by itself a number of times equal to the Second Operand (the exponent)

Question 19

What is the Exponent in an Exponentiation Operator?

Answer 19

An Exponent is the Second Operand

Question 20

Write a code that contains the Exponentiation Operator.

Answer 20

const exponent = 10
const result = 7**exponent

Question 21

What are ways to express the Exponentiation Operator in Human Language Form?

Answer 21

You can say “ten to the power of seven” or “ten to the seventh power” to express the Exponentiation Operator in Human Language Form.

Question 22

Which symbol can be used to combine strings together?

Answer 22

The symbol + can be used to combine strings together.

Question 23

What is a String?

Answer 23

A String is a sequence of characters, used typically to represent text.

Question 24

What is ‘String Concatenation’?

Answer 24

String Concatenation is using the + operator to combine two Strings together.

Question 25

What does String Concatenation allow you to do?

Answer 25

String Concatenation allows us to join Strings together to form a new String.

Question 26

Where is the String Concatenation in - const greeting = 'hello' + 'world' - ?

Answer 26

'hello' + 'world'

Question 27

Can you Concatenate Variables holding String Values?

Answer 27

Yes, you can concatenate variables holding string values.

Question 28

How would you Concatenate - const area = 'North' & - const coolKids = 'coders' - ?

Answer 28

const coolestKidsOnThePlanet = area + coolKids // North Coders

Question 29

What is Type Coercion in JavaScript?

Answer 29

Type Coercion is the process of converting a value from one data type to another data type either automatically or implicitly by the JavaScript Coding Engine during the code execution.

Question 30

What is the negative side of piecing together complex strings with the + operator?

Answer 30

The negative side of piecing together complex strings with the + operator is that it could lead you with unwieldy expressions.

Question 31

Which Mechanism provides support for managing strings made up of variables?

Answer 31

Template Literals are a Mechanism used for managing strings made up of different variables.

Question 32

Why does piecing together complex strings with the + operator lead to unwieldy expressions?

Answer 32

It can quickly become messy, especially with variables and new lines. Missing the + operator, a space, or a quotation mark can lead to syntax errors and unexpected results. Using + for multi line strings can be clunky which is harder to edit and visually cluttered.

Question 33

Should you use the Template Literal or the + Operator for Easy, Simple Strings that need to be combined?

Answer 33

You should use the + operator for combining strings that are easy and simple. You should use the Template Literal for combining strings that are more complex.

Question 34

What is the third quotation mark that can be used to write a string?

Answer 34

A backtick is the third quotation mark that can be used to write a string.

Question 35

Which notation are variables placed inside during the process of Template Literal?

Answer 35

The backtick notation is used.

Question 36

Where is the Template Literal demonstrated in - const player = 'Alexandra' const team = 'Red' const description = `${player} is in the ${team} team!`

Answer 36

The template literal is demonstrated in - `the backticks being used.

Question 37

What is the placeholder symbol in Template Literal?

Answer 37

The Placeholder symbol in the Template Literal Process is ${}. Variables are placed inside the placeholder.

Question 38

What is it sometimes called when Strings are conducted with 'Placeholders' for variables?

Answer 38

It is sometimes called Interpolation.

Question 39

What is Interpolation?

Answer 39

The process of embedding variables and/or expressions inside of a string to create a dynamic output.

Question 40

How do you achieve Interpolation using JavaScript?

Answer 40

You use Template Literals to achieve Interpolation in JavaScript.

Question 41

What is the Index?

Answer 41

The Index is the position of a piece of data.

Question 42

What is Indexing useful for?

Answer 42

Indexing is useful for searching and sorting data.

Question 43

How can you use Indexes in a string?

Answer 43

In a string, you can use indexes to identify the character at any given position.

Question 44

What number do Indexes in JavaScript start at?

Answer 44

Indexes in JavaScript start at the number zero.

Question 45

What kind of Indexed are Strings?

Answer 45

Strings are zero-indexed because the first character is indexed at 0 and then counts upwards.

Question 46

What index positions do the characters in a five letter string have?

Answer 46

0,1,2,3,4 are the index positions for the five letters within a five letter string.

Question 47

Which Syntax is used in JavaScript to access the characters in a string?

Answer 47

The [] square bracket syntax is used for accessing a character within a string. You place the characters Index Position within the square bracket syntax.

Question 48

Which character will be evaluated in: const greeting = hello const firstCharacter = greeting[o]

Answer 48

'h' will be the character evaluated

Question 49

Which character will be evaluated in: const greeting = hello const secondCharacter = greeting[1]

Answer 49

'e' will be the character evaluated

Question 50

What would happen if we tried to access the character at a position greater than the number of characters in a string?

Answer 50

You would come across the undefined data type.

Question 51

What does 'undefined' represent?

Answer 51

'undefined' represents data that cannot be found.

Question 52

What can we think of 'Property' as?

Answer 52

We can think of Property as being a way to access more information about a piece of data.

Question 53

What Property do Strings have?

Answer 53

Strings have the Length Property

Question 54

What can we use a String's Length Property for?

Answer 54

We can use the length property to identify how many characters there are in a string.

Question 55

What syntax is used in order to use a Property?

Answer 55

Dot notation syntax is used = .

Question 56

What is a common reason for using the length property in JavaScript?

Answer 56

A common reason for using the length property in Javascript is to access the last character in a string without knowing the length of the string as we write the code.

Question 56

Where is the Property Syntax in: const exampleLength = example.length

Answer 56

the Property Syntax is demonstrated in the dot notation syntax in - "example.length"

Question 57

How do you use the length property to access the last character in a string without knowing the length of the string as we write the code?

Answer 57

You write the variable of the string followed by the variable.length - 1 wrapped in square bracket notation.

Question 58

What are Methods?

Answer 58

Methods are Actions that can be performed on data.

Question 59

How do you capitalise all characters within a string to become UpperCase?

Answer 59

you attach the dot notation syntax before writing toUpperCase followed by parantheses ()

Question 60

How do you capitalise all characters within a string to become LowerCase?

Answer 60

you attach the dot notation syntax before writing toUpperCase followed by parantheses ()

Question 61

What is the difference between the syntax used for using a method and the syntax used for accessing it's property?

Answer 61

They are similiar because they both use dot notation syntax however because methods are a function they require parantheses () to use them.

Question 62

What is Parantheses?

Answer 62

()