44 lines
1.2 KiB
Markdown
44 lines
1.2 KiB
Markdown
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# out of bounds
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The behavior of functions whose parameter values are out of bounds.
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Many of the BBC micro:bit functions have parameters. If a parameter is an unexpected value, the parameter is considered *out of bounds*.
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For example, the [plot](/microbit/reference/led/plot) function has two parameters:
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### syntax
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```
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export function plot(x: number, y: number)
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```
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### parameters
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* x - the *x coordinate* or horizontal position (0, 1, 2, 3, 4)
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* y - the *y coordinate* or vertical position (0, 1, 2, 3, 4)
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### out of bounds
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here's an example of code with an out of bounds parameter (the *x* and *y* parameters are outside the expected range of 0-4):
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```
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led.plot(9, -21)
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```
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### what happens?
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Typically, when a parameter supplied to a function is out of bounds that function does nothing (as if the function never executed). So, in the above case, the LED screen will not change.
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### return value
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If you call the `point` function with an out of bounds parameter, the function returns `false`:
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```
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let on = led.point(5, -5)
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```
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### see also
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For more information on the out-of-bounds behavior of a function, see the documentation for that [function](/microbit/js/contents).
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