- Operating mode
- Existing computations
<Array>.Reduce (Function) In french: <Tableau>.Agrège Applies a computation to each element of a WLanguage array.
arrValue is array of int = [1,2,3,4,5] TheSum is integer TheSum = arrValue.Reduce((Value, TheSum) => { RESULT Value + TheSum }, 0) // Note: this example is for illustrative purposes ; to find the sum of elements of an array, // it is preferable to use the Sum function
Syntax
<Result> = <Array>.Reduce(<Operation to perform> [, <InitialValue>])
<Result>: Type corresponding to the result Result of the requested reduce operation. <Array>: WLanguage array Name of Array variable to use. This array must be a one-dimensional array. <Operation to perform>: WLanguage procedure Name of WLanguage procedure to run. This procedure can be: - a global or local procedure,
- an internal procedure.
It is also possible to directly use a lambda. <InitialValue>: Optional parameter, type corresponding to the initial value Initial value to use the first time the <Operation to perform> procedure is run. Remarks Operating mode The <Operation to perform> procedure is called a first time with two parameters: - the first element of the array,
- the initial value specified with <Initial value>.
The procedure is then called for all other elements of the array with two parameters: - the element of the array,
- the value returned by the previous call.
Illustrative exampleLet's study the following example:
arrValue is array of int = [1,2,3,4,5] TheSum is integer TheSum = Reduce(arrValue, (Value, TheSum) => { RESULT Value + TheSum }, 0)
In this example, the code:
TheSum = arrValue.Reduce((Value, TheSum) => { RESULT Value + TheSum }, 0)
is equivalent to the following code:
TheSum = arrValue.Reduce(Add, 0) INTERNAL PROCEDURE Add(Value, Total) RESULT Value + Total END
With this internal procedure, the calculation can be broken down as follows: - IntermediateResult1 = Add (t[1], InitialValue): in the example Add( 1, 0 ) -> 1
- IntermediateResult2 = Add (t[2], IntermediateResult1): in the example Add( 2, 1 ) -> 3
- ...
Remark: this example is for illustrative purposes; to find the sum of elements of an array, it is preferable to use Sum. Existing computations The most common computations are available in WLanguage:
| | Versions 17 and laterMean New in version 17Mean Mean | Calculates the mean of several elements: - elements found in an array,
- numeric values, ...
| Versions 17 and laterSum New in version 17Sum Sum | Calculates the sum of the array elements. |
Business / UI classification : Neutral code
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