CODEWITHSUNDEEP
swiftif-statementswift3
MoXyLe
MoXyLe

Reputation: 15

How if works there?

 func sortFunc (array: [Int], closure: (Int?, Int) -> Bool) -> Int {
     var tempVar: Int? = nil
      for value in array {
           if closure (tempVar, value) {
              tempVar = value
           }
        }

    return tempVar!
 }

In this code I can't understand this:

    if closure (tempVar, value) {
   tempVar = value
}

Can you explain what closure(tempVar, value) means? I tried to find info in documentation, but there is nothing, that can help me.

Upvotes: 1

Views: 64

Answers (2)

Forest Kunecke
Forest Kunecke

Reputation: 2160

Let's break this down. Looking at the method signature, you can see the definition of closure:

func sortFunc (array: [Int], closure: (Int?, Int) -> Bool) -> Int

What this means is that there is a parameter named closure for the function sortFunc which must have two arguments, an Int? and Int, that returns a Boolean value.

So what does that even mean?

That means we are passing a function to sortFunc as a parameter. An example of this would be something like this:

func myFunction(_ temporaryValue: Int?, value: Int) {
    // return a boolean value
    return temporaryValue != nil
}

When you call if closure(tempVar, value) it evaluates the function passed provided with the arguments of tempVar and value and returns a boolean (true/false) based on the results of that function.

Upvotes: 1

EmilioPelaez
EmilioPelaez

Reputation: 19884

closure is a block of code that takes two parameters, one Int? and one Int, and returns a Bool.

It can be called like a function and will return a value.

When you do this if closure(tempVar, value), you are calling that block of code with those two parameters, so it will return a boolean value.

Upvotes: 1

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