24 lines
1.0 KiB
Plaintext
24 lines
1.0 KiB
Plaintext
[[painless-functions]]
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=== Functions
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A function is a named piece of code comprised of one-to-many statements to
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perform a specific task. A function is called multiple times in a single script
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to repeat its specific task. A parameter is a named type value available as a
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<<painless-variables, variable>> within the statement(s) of a function. A
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function specifies zero-to-many parameters, and when a function is called a
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value is specified per parameter. An argument is a value passed into a function
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at the point of call. A function specifies a return type value, though if the
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type is <<void-type, void>> then no value is returned. Any non-void type return
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value is available for use within an <<painless-operators, operation>> or is
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discarded otherwise.
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You can declare functions at the beginning of a Painless script, for example:
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[source,painless]
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---------------------------------------------------------
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boolean isNegative(def x) { x < 0 }
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...
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if (isNegative(someVar)) {
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...
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}
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--------------------------------------------------------- |