Closures In Swift And It’s Related Importance

Tudip Technologies
1 min readMay 16, 2022

Closures in Swift

Closure is everywhere in Swift. If you are working with Swift you must be using closure.

What is closure?

Closures are self-contained blocks of functionality that can be passed around and used in your code

  • Swift Documentation.
Let’s see an example of closure:{Code}let isEven = { (value: Int) -> Bool inreturn (value % 2 == 0) ? true : false}print("5 is \(isEven(5))"){Code}

Code Snippet — 1

Everything within the brackets { } is called as the Closure expression.

Closure expressions are unnamed closures written in a lightweight syntax that can capture values from their surrounding context

  • Swift documentation
Closure expression syntax:{ (parameters) -> return type instatement}

In code snippet — 1

  • The parameter name is “value” which is of type “Int”.
  • The return type is “bool”.
  • Statement and parameters are separated by “in” keyword.

There are various optimizations provided to the closure expression.

  1. Closure expression can Infer types from it context.

Swift infers the type of the parameter and type of the value it returns from the context.

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