102 lines
2.0 KiB
Markdown
102 lines
2.0 KiB
Markdown
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# Function parameters
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## Function with 1 parameter
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Place the parameter's datatype after the function's name, then the name of the parameter.
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For example, a function that takes a `Str` as parameter is defined as follows:
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```misti
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fun sayHello(Str name) =
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// Body of the function
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```
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Then the parameter `name` can be used.
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```misti
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fun sayHello(Str name) =
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print("Hello {name}")
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```
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## Function with 2 or more parameters
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The parameters are separated with commas:
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```misti
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// 2 parameters: x and y, both Int
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fun add(Int x, Int y) -> Int =
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x + y
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```
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```misti
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// 3 parameters
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fun substring(Str input, Int start, Int end) -> Str =
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// Logic...
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```
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And so on.
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## Generic parameters
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Generic parameters consist of an uppercase letter enclosed in square brackets.
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They are placed after the function name, but before the parameters list.
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```misti
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fun getItemAt[T](Array[T] arr, Int pos) -> T =
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// Function body
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```
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When calling the function, the generic parameter is placed in the same position.
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```misti
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val thirdName = getItemAt[String](names, 2)
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```
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If the generic parameter can be inferred, it's not necessary to put it.
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```misti
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// Will be a String, inferred
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val thirdName = getItemAt(names, 2)
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```
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## Named parameters
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When calling a function you can link the name of an argument to its value.
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In the following function, `substring` has 3 parameters: `string`, `start` and `end`.
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```misti
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fun substring(Str string, Int start, Int end) =
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// Body of the function
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```
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Then, when calling the function, you can specify each parameter and their values.
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```misti
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// Without named parameters
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substring("Hello, world!", 7, 12)
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// With named parameters
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substring(string: "Hello, world!", start: 7, end: 12)
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substring(
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string: "Hello, world!",
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start: 7,
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end: 12,
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)
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```
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This will return `"world"`.
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You can do computations with named parameters as well.
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```misti
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substring(string: "Hello, world!", start: 12 - 5, end: 48 / 4)
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substring(
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string: "Hello, world!",
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start: 12 - 5,
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end: 48 / 4,
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)
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```
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