# EXAMPLE - ARRAYINDEXOF and ARRAYRIGHTINDEXOF Functions

This example illustrates how to convert the index value of an array for a specified value searching from left to right and right to left by using ARRAYINDEXOF and ARRAYRIGTHINDEXOF functions.

Functions:

Item

Description

ARRAYINDEXOF Function

Computes the index at which a specified element is first found within an array. Indexing is left to right.

ARRAYRIGHTINDEXOF Function

Computes the index at which a specified element is first found within an array, when searching right to left. Returned value is based on left-to-right indexing.

Source:

The following set of arrays contain results, in order, of a series of races. From this list, the goal is to generate the score for each racer according to the following scoring matrix.

Place

Points

1st

30

2nd

20

3rd

10

Last

-10

Did Not Finish (DNF)

-20

Results:

RaceId

RaceResults

1

["racer3","racer5","racer2","racer1","racer6"]

2

["racer6","racer4","racer2","racer1","racer3","racer5"]

3

["racer4","racer3","racer5","racer2","racer6","racer1"]

4

["racer1","racer2","racer3","racer5"]

5

["racer5","racer2","racer4","racer6","racer3"]

Transformation:

Note that the number of racers varies with each race, so determining the position of the last racer depends on the number in the event. The number of racers can be captured using the following:

Transformation Name New formula Single row formula ARRAYLEN(RaceResults) 'countRacers'

Create columns containing the index values for each racer. Below is the example for racer1:

Transformation Name New formula Single row formula ARRAYINDEXOF(RaceResults, 'racer1') 'arrL-IndexRacer1'
Transformation Name New formula Single row formula ARRAYRIGHTINDEXOF(RaceResults, 'racer1') 'arrR-IndexRacer1'

You can then compare the values in the two columns to determine if they are the same.

Note

If ARRAYINDEXOF and ARRAYRIGHTINDEXOF do not return the same value for the same inputs, then the value is not unique in the array.

Since the points awarded for 1st, 2nd, and 3rd place follow a consistent pattern, you can use the following single statement to compute points for podium finishes for racer1: computing based on the value stored for the left index value:

Transformation Name Conditional column if...then...else {arrayL-IndexRacer1} < 3 (3 - {arrayL-IndexRacer1}) * 10 0 'ptsRacer1'

The following transform then edits the ptsRacer1 to evaluate for the Did Not Finish (DNF) and last place conditions:

Transformation Name Edit column with formula ptsRacer1 IF(ISNULL({arrayL-IndexRacer1}), -20, ptsRacer1))

You can use the following to determine if the specified racer was last in the event:

Transformation Name Edit column with formula ptsRacer1 IF(arrR-IndexRacer1 == countRacers, -10, ptsRacer1)

Results:

RaceId

RaceResults

countRacers

arrR-IndexRacer1

arrL-IndexRacer1

ptsRacer1

1

["racer3","racer5","racer2","racer1","racer6"]

5

3

3

0

2

["racer6","racer4","racer2","racer1","racer3","racer5"]

6

3

3

0

3

["racer4","racer3","racer5","racer2","racer6","racer1"]

6

5

5

-10

4

["racer1","racer2","racer3","racer5"]

4

0

0

20

5

["racer5","racer2","racer4","racer6","racer3"]

5

null

null

-20