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List/Set.at(N)


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Operator Altered: 

 Function   [other Function type actions]

 Item   [operators of similar scope]

 Data manipulation   [other Data manipulation operators]

 Baseline

 


List.at(N)

This returns the Nth value of the List as a string. List can be either Set or List type attributes (or string literal, regex pattern, or expression equivalents thereof).

The operator is zero-based, i.e. an N value of 0 returns the first list item, an N of 1 returns value #2, etc. If the value of N exceeds the number of items in the list an empty string (blank value) is returned. A negative number returns an item numbering in reverse - but one-based not zero-based - so '-1' returns the last item on the list, '-2' the last but one item, etc..

Examples (where $MyList is "ant;bee;cow"):

$MyString = $MyList.at(0) returns "ant"

$MyString = "XX;YY;ZZ".at(2) returns "ZZ"

$MyString = $MyList.at(5) returns "" (nothing) 

$MyString = $MyList.at(-2) returns "bee"

The .at() function is also useful for accessing values from look-up tables by providing the relevant key. Consider a look-up list:

$RegionList="AL:South;AK:NorthWest;default:North" 

This now allows actions like:

$Region=$RegionList.at("AL") 

or

$Region=$RegionList.at($State)