| Original Message (ID '125489') By Nasser M. Abbasi: |
| funcTest[list_List, str_String, count_Integer] := list[[count]] = str
list1={a,b}
funcTest[list1,"Help",1]
Results in:
{a, b}
Set::setps: {a,b} in the part assignment is not a symbol. >>
Yet,
list1[[1]]="Help!!"
{Help!!,b}
Works. What is the problem?
-----------------------------------
Mathematica passes things by value. You can't update a function parameter.
To update an input, you must first make a copy of it, then update the copy, and return the copy.
-------------------
funcTest[list_List,str_String,count_Integer]:=Module[{c=list},
c[[count]]=str;
c
]
list1={a,b};
list1=funcTest[list1,"Help",1]
----------------------
{"Help", b}
|
|
