If assign in Swift

In Swift programming language, if let and if var statements are used to safely unwrap optional values. These statements are conditional and will only execute the code inside the curly braces {} if the optional value is not nil. Here are some examples of using if let and if var to assign optional values:

### Using if let statement

let optionalName: String? = "John Doe"
if let name = optionalName {
    print("Hello \(name)")
} else {
    print("Name is nil")
}
/* Output:

Hello John Doe

*/

In the above example, the optionalName variable is assigned a non-nil value "John Doe". The if let statement safely unwraps the optionalName variable and assigns its value to the name constant. The print statement inside the curly braces is executed since the optionalName variable is not nil.

### Using if var statement

var optionalGreeting: String? = nil
if var greeting = optionalGreeting {
    greeting = "Hello"
    print(greeting)
} else {
    print("Greeting is nil")
}
/* Output:

Greeting is nil

*/

In the above example, the optionalGreeting variable is assigned a nil value. The if var statement safely attempts to unwrap the optionalGreeting variable and assigns its value to the greeting variable (which is a mutable var). However, since the optionalGreeting variable is nil, the else block is executed and prints "Greeting is nil".