manual:chapter3:lists

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manual:chapter3:lists [2021/08/15 13:58]
claudio [Operating with Lists] 		manual:chapter3:lists [2021/08/15 14:51] (current)
claudio [Elements within a List]
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 For example, lists can be used to quickly apply the same operation to more than one value: For example, lists can be used to quickly apply the same operation to more than one value:
  
 +<code>
 +2:                     { 1 2 3 }
 +1:                             1
 +……………………………………………………………………………………
 ++
 +</code>
 +will result in adding ''1'' to each element on the list: ''{ 2 3 4 }''.
  
 +There's operations that are exclusive to lists, for example the command ''ADD'' will concatenate two lists, or append 1 element at the end of the list.
 +
 +<code>
 +2:                     { 1 2 3 }
 +1:                             1
 +……………………………………………………………………………………
 +ADD
 +</code>
 +will result in ''{ 1 2 3 1 }'' and
 +<code>
 +2:                     { 1 2 3 }
 +1:                     { 4 5 6 }
 +……………………………………………………………………………………
 +ADD
 +</code>
 +will result in ''{ 1 2 3 4 5 6 }''
 +
 +Other common commands that operate on lists are:
 +
 +  * ''→LIST'': Creates a list from loose objects in the stack
 +  * ''LIST→'': Split a list into individual objects in the stack
 +  * ''SORT'': Sort the elements of a list
 +  * ''REVLIST'': Reverses the order of a list
 +
 +
 +==== Elements within a List ====
 +
 +Elements in a list can be referred to by a numeric index. The index starts at ''1'' for the first element of the list. To get an element from a list, the ''GET'' command is used:
 +<code>
 +2:                  { 11 12 13 }
 +1:                             2
 +……………………………………………………………………………………
 +GET
 +</code>
 +will result in ''12''.
 +
 +Replacing an element is done via the ''PUT'' command:
 +
 +<code>
 +3:                  { 11 12 13 }
 +2:                             2
 +1:                             3
 +……………………………………………………………………………………
 +PUT
 +</code>
 +will result in ''{ 11 3 13 }'' because the object ''3'' replaced the object at index ''2''
 +
 +Elements of a list can also be accessed from within algebraic expression (read-only) by giving the list a name (store the list in a variable using ''STO'' or ''LSTO'') and then including the index in parenthesis, much like a mathematical function.
 +For example, assuming the list ''{ 11 12 13 }'' was stored in variable ''L'', evaluating ''%%'L(2)+10'%%'' will result in ''22'' as expected.
 +==== Procedures with Lists ====
  • manual/chapter3/lists.1629061129.txt.gz
  • Last modified: 2021/08/15 13:58
  • by claudio