Optional Binding

In swift  we deal with optional value . To deal  with optional values swift provides us forced unwrapping , optinal binding and optional chaining. Today we discuss forced unwrapping and option  binding 
Forced Unwrapping : When we use forced wrapping to a  variable. It means that we are getting value of it. It cannot be nil.We are ! for forced wrapping.

let  myString  = "123"
let convertToInt = Int(myString!)

Explanation: Here we know that 123 is in string format and we are converting it into  Int value.


Optional Binding: You use optional binding to find out whether an optional contains a value, and if so, to make that value available as a temporary constant or variable. Optional binding can be used with if and while statements to check for a value inside an optional, and to extract that value into a constant or variable, as part of a single action. Lets take the same example.

Example: 
let  myString  = "swift"
let convertToInt = Int(myString)

Output : nil 

Its output is nil because we are converting  words to  Int value.I mean that's not possible. To deal with absence of value we use optional binding.

Optional Binding Syntax :

if let constantName = someOptional {
      //statements
}
if let tempValue = convertToInt {
print("converted successfully")
} else {
  print("enable to convert")
 }

Advantage of Optional Binding 
we can avoid crashes in the application  in the absence of value.