64 lines
1.6 KiB
Markdown
64 lines
1.6 KiB
Markdown
# Call a Function
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How to call a function in your code. #docs #function #call #language
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### @parent js/language
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Type a function name in your code to call an existing [function](/microbit/js/function) in your script.
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### Call a function
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1. In the Touch Develop editor, click a line of code to open the on-screen [Code Keyboard](/microbit/js/editor).
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2. Click `code` to see the functions in your script.
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2. Click the function that you want to call.
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3. Click `store in var` to store the return value in a variable.
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### Example: the square function
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Here's a function called `square`, with a [Number](/microbit/reference/types/number) input parameter:
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```
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/**
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* // returns the square of the input parameter x
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* @param x TODO
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*/
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export function square(x: number) : number {
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let result: number
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return x * x
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return result
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}
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```
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The following code calls the `square` function, passing it an input parameter (`x`), and storing the return value in the `result` variable:
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### ~hide
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```
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let x1 = 2
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```
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### ~
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```
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let result1 = square(x1)
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```
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Or this code, which displays the result of the `square` function (without first storing the value in a variable):
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```
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basic.showNumber(square(x1), 150)
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```
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### See all your functions
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To see a list of the functions in a script, open the script and then click `script` (in the upper-right corner). All of the functions appear under the **code** heading. Click on a function to open it in the editor.
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### See also
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[function parameters](/microbit/js/functionparameters), [create a function](/microbit/js/function), [return statement](/microbit/js/return)
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