How to Unwrap an Optional Variable in Swift?

Swift – Unwrap Optional Variable

To unwrap an optional variable in Swift, use exclamation mark ! character after the variable name in an expression.

The syntax to unwrap a variable x is

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x!

In the following program, we will define an optional integer variable, and unwrap it in an arithmetic expression.

main.swift

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var x : Int? = 25
let result = x! + 10
print(result)

Output

If value in this optional variable is nil, then using this optional variable causes runtime error.

main.swift

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var x : Int?
let result = x! + 10
print(result)

Output

In this Swift Tutorial, we learned how to unwrap an optional variable in Swift programming.