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This article mainly explains "how to customize Scala closures". Interested friends may wish to have a look. The method introduced in this paper is simple, fast and practical. Let's let the editor take you to learn how to customize Scala closures.

A closure is a function and the return value depends on one or more variables declared outside the function.

Generally speaking, a closure can be simply thought of as another function that can access local variables in a function.

Such as the anonymous function below:

Val multiplier = (i:Int) = > I * 10

There is a variable I in the body of the function, which is used as an argument to the function. Like another piece of code below:

Val multiplier = (i:Int) = > I * factor

There are two variables in multiplier: I and factor. One of the I is the formal argument of the function, and when the multiplier function is called, I is assigned a new value. However, factor is not a formal parameter, but a free variable. Consider the following code:

Var factor = 3

Val multiplier = (i:Int) = > I * factor

Here we introduce a free variable factor, which is defined outside the function.

The function variable multiplier defined in this way becomes a "closure" because it refers to the variable defined outside the function, and the process of defining this function is to capture the free variable to form a closed function.

Complete instance

Object Test {

Def main (args: Array [String]) {

Println ("muliplier (1) value =" + multiplier (1))

Println ("muliplier (2) value =" + multiplier (2))

}

Var factor = 3

Val multiplier = (i:Int) = > I * factor

}

Execute the above code, and the output is as follows:

$scalac Test.scala

$scala Test

Muliplier (1) value = 3

Muliplier (2) value = 6 so far, I believe you have a deeper understanding of "how to customize Scala closures". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

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