A simple example is shown below. As the name implies the block of statement for if executes if the condition is satisfied.

let a = 20
if a == 20 {
println("\(a)")
}

Output

20

if else example

A simple if else example is shown below.

let a = 10
if a == 20 {
println("\(a)")
}
else{
println("Not 20")
}

Output

Not 20

if else ladder example

let a = 3
if a == 1 {
println("Number is 1")
}
else if a == 2 {
println("Number is 2")
}
else if a == 3 {
println("Number is 3")
}
else{
println("UnKnown number")
}

Output

Number is 3

Optionals and if statement

var name: String?
if let tempName = name {
    println("value present")
}
else {
    println("NIL")
}

Output

NIL

You can see that optionals can be checked with if let syntax. Also, it copies the variable locally and helps us not making changes to the original value.