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Definitions of, and, Differences between Column, Name, Column Name, String, Symbol, Global Name, Item.

kardopaska

Community Trekker

Joined:

Feb 24, 2016

What are the definitions of, and, differences between these terms?

  1. Column
  2. Name
  3. Column Name
  4. String
  5. Symbol
  6. Variable
  7. Global Name
  8. Item

It is so frustrating to see these terms used interchangeably in the scripting index or other documentation, especially when the style of the documentation is written colloquially without regard to meaning of a term within a programming context.

For instance:

dt_name = Current Data Table() << Get Name();

then,

type(dt_name);

will return

"String"


But the message i just sent was get NAME!?  Then you go into scripting index and the description of "name" is

A name is simply something to call an item.  Names are used for both variables and functions...

​What? what's an item? Wait what? Names can be used for variables too?


Please tell me I'm not the only one...


1 REPLY
txnelson

Super User

Joined:

Jun 22, 2012

JSL can be a big bite to chew all at once.  Your question asking for the definition of a list of items, can really only be answered once the context of each of the items is known.

Let's take the first item: Column

It can be refering to a column of data in a data table, or a column in a matrix, or it could be referring to the function Column(), which allows for the referencing of a column by the position in a data table   Column(3);

The same multiple references for the next item Name can also be made.

In an attempt clear up some of your confusion, I will explane why I believe you got the results that you did, in the little script that you included:

    dt_name = Current Data Table() << Get Name();

The Current Data Table() function returns a pointer to the data table that is currently "in focus" or is the "active" data table.  So in your example,

    dt_name = current data table()

would return to the memory variable dt_name the value

    Data Table("String")

I claim that you have a data table named "String", because the next item it will be evaluating is the

    << Get Name

and what it will do, is to take the Current Data Table(), which we know has the value of Data Table("String") and will return it to the memory variable, the name of the current data table, thus changing the memory variablef dt_name's value to:

    "String"

So now when you type(dt_name), it displayes the value

    "String"

I found that by reading/scanning the first 100 pages or so of the Scripting Guide, all of the components of JSL fell into place.  If you are not aware, the Scripting Guide is available under JMP pull down menus:

    Help==>Books==>Scripting Guide

I hope this is helpful to you

Jim