Update Array Recursively

RE: Update Array Recursively

Stefan Helzle — Mon, 08 Nov 2021 07:55:21 GMT

OK. So to keep the data in a specific order, the actual values do not matter as long as they are ascending and unique.

A code snippet similar to the below, should update the rollNumbers. There is no complex logic necessary.

a!forEach(
  items: local!list,
  expression: a!update(
    fv!item,
    "rollNumber",
    fv!index
  )
)

RE: Update Array Recursively

shamima0001 — Mon, 08 Nov 2021 06:58:37 GMT

To answer your questions, please have a look on the inline comments :

Where is that data coming from? [ Data is coming form a table in database ]

Is this the whole list or just a part of it? [ it is the whole list ]

What is the meaning of that "rollNumber"? [ '"rollNumber" is an integer value field]

Is it used in other table as a foreign key or something? Sorting? [ It is not used in other table as foreign key, but used to sort the whole table data]

Then, how is that data added? By a user in an interface? [ data is added from a dropdown in an interface]

Hope this answers your question.

RE: Update Array Recursively

Stefan Helzle — Mon, 08 Nov 2021 06:50:18 GMT

Hm ... this really depends on your actual use case.

Where is that data coming from? Is this the whole list or just a part of it? What is the meaning of that "rollNumber"? Is it used in other table as a foreign key or something? Sorting?

Then, how is that data added? By a user in an interface?

RE: Update Array Recursively

shamima0001 — Mon, 08 Nov 2021 06:20:42 GMT

Can you help me understand with an example, please ?

RE: Update Array Recursively

Stefan Helzle — Sat, 06 Nov 2021 15:14:11 GMT

Why not just add the names and then renumber the whole list? That would be easy to do with a foreach and a!update.

RE: Update Array Recursively

shamima0001 — Sat, 06 Nov 2021 14:28:17 GMT

My apologies, actually its not just array of integers but array of CDTs. I have updated the question above.

Please help me with it.

RE: Update Array Recursively

Stewart Burchell — Fri, 05 Nov 2021 16:09:26 GMT

Like a lot of problems, you can break this down into smaller problems to solve.

solve how to take you array and insert ONE new value into it
1. solve inserting a value that doesn't yet exist in the array
2. solve inserting a value that does exist in the array
solve how to invoke the above for a list of values

For 1 you can write an expression rule that takes as its input your array of integers that you want to modify and a single integer that you want to insert into the array.

For 2 there is the reduce() function which you can use to recursively call your new expression.