Session 2: Learn to Code with SWIFT

Question 1

What is a variable?

Answer 1

Used to store information like some labels to be referred later and stored in memory. Variables are containers of information and link between users and software.

Question 2

Give an example of variable and how it stores in computer?

Answer 2

For example my age is 23. But computer only works with 0 and 1 so, 23 is for us. Now age is a variable and it’s value which is 23 stores inside the RAM(Random Access Memory). In programming perspective: var age = 23.

Question 3

What is an assignment operator?

Answer 3

Or = assigns the variation to an operator which can be string “like this” or value e.g. 30.

Question 4

What can be after assignment operator?

Answer 4

Assigns the value to variable.

Question 5

3 main kinds of operators?

Answer 5

Unary(single), Binary(Double) and Ternary(Three)

Question 6

Write the samples in codes for operators?

Answer 6

Unary(Only amICoolPerson)—> var amIACoolPerson = true, amICoolPerson = !amICoolPerson. Binary(name and this is great)—> var name = “this is great”. ….

Question 7

What is string and it’s length?

Answer 7

A finite sequence of characters(either word or symbols or letter). The length can be from zero to a number.

Question 8

What is string manipulation? Using a string from another variable and using inside another variable like: var name = “ali” , var family = “sadeghi” var fullName = name “ “ family.

Answer 8

Using a string from another variable and using inside another variable like: var name = “ali” , var family = “sadeghi” var fullName = name “ “ family.

Question 9

What is string interpolation?

Answer 9

Using all previously used strings inside new string by using ((variable)) like var fullName2 = “(first) (last) is (age) years old”

Question 10

What is append function?

Answer 10

When we want to add an object at the end of a variable like: var fullName.append = “AAA” —> Becomes: ali sadeghiAAA

Question 11

Write sample code contains strings to change bad words?

Answer 11

var sentence = “what the F* you are As*”, if sentence.contains(“f*) || sentence.contains(“As*) { sentence.replaceingOccurrences (of: “f*” , with “Googooli”

Question 12

What are the main types of Numbers?

Answer 12

3 groups: Integer, Float and Double

Question 13

What is Integer?

Answer 13

Numbers with no fraction. It can be either positive, negative or zero.

Question 14

What is difference between signed and assigned integers?

Answer 14

When we put a number we assign the integer to a limited number of integers can carry. e.g. UInt8 only can carry 8 digits. But if we don’t mention anything SWIFT automatically fixes upon needs.

Question 15

What is Double Data type?

Answer 15

For when we use long digits or fractional we use Double. Double type is the preferred type suggested by SWIFT by default.

Question 16

What is Float type?

Answer 16

It is like Double type but with fewer and shorter digits.

Question 17

What is Argument?

Answer 17

Argument is also know as parameter.

Question 18

What is fun?

Answer 18

It is the Function abbreviation

Question 19

What is Return Type?

Answer 19

After we define the function name and dedicate it’s argument before writing the function formula we use Return Type which clears out what will be the final type of outcome. It is like this: (—>Int {

Question 20

What is Let and Return?

Answer 20

After the Return type inside the parenthesis we should write the function after let NAME and then use return of NAME

Question 21

How does a function work? From start to end.

Answer 21

First—> Write the function and choose a name and mention it’s argument and their variable type

Question 22

Write an example: We want to buy a shoe 350.00 $ if our bank account is more than the price. Write a formula?

Answer 22

here is the formula

Question 23

Review key vocabs from Session 2 in your mind: Function, Array, Variable, Operator, Assignment Operator, Logical Operator, Comparison Operator, Value, Element, Array Assignment….