A variable refers to a storage location in the computer’s memory that one can set aside to save, retrieve, and manipulate data.
var score = 0
Constants refer to fixed values that a program may not alter during its execution. One can be declared by using the
let pi = 3.14
Swift supports arithmetic operators for:
var x = 0 x = 4 + 2 // x is now 6 x = 4 - 2 // x is now 2 x = 4 * 2 // x is now 8 x = 4 / 2 // x is now 2 x = 4 % 2 // x is now 0
Type annotation can be used during declaration.
The basic data types are:
Int: integer numbers
Double: floating-point numbers
String: a sequence of characters
Bool: truth values
var age: Int = 28 var price: Double = 8.99 var message: String = "good nite" var lateToWork: Bool = true
String interpolation can be used to construct a
String from a mix of variables, constants, and others by including their values inside a string literal.
var apples = 6 print("I have \(apples) apples!") // Prints: I have 6 apples!
Compound Assignment Operators
Compound assignment operators provide a shorthand method for updating the value of a variable:
+=add and assign the sum
-=subtract and assign the difference
*=multiply and assign the product
/=divide and assign the quotient
%=divide and assign the remainder
var numberOfDogs = 100 numberOfDogs += 1 print("There are \(numberOfDogs) dalmations!") // Prints: There are 101 dalmations!