Printing names of indexed variables instead of values

Question

I'd like to display only the variable (indexed variable) name (in symbol form, not in string form) instead of its value in Mathematica. Say I have a variable foo[i] with i being the index, How do I get something like {foo[1], foo[2]} as output?

I have tried i = 1; HoldForm[foo[i]] but Mathematica seems to hold all evaluations, including replacing the index i with its value. HoldForm[foo[i]] /. i -> i also won't work.

There exists another thread in SE that connects with this question, but it doesn't seem to work either.

Display variable name instead of value

HoldForm[foo[i]] /. i -> 1 or HoldForm[foo[i]] /. i -> j will work. — Jinxed, Mar 18 '15 at 14:33
Also With[{i=1},HoldForm[foo[i]]] works. As does i=1;With[{i=i},HoldForm[foo[i]]]. — celtschk, Mar 18 '15 at 16:43

David G. Stork · Accepted Answer · 2015-03-18T14:48:16.177

4

I believe this is what you're seeking:

HoldForm[foo] /@ Range[2]

and if you want individual elements:

(HoldForm[foo] /@ Range[2])[[1]]

and

(HoldForm[foo] /@ Range[2])[[2]]

edited Mar 18 '15 at 14:48

answered Mar 18 '15 at 14:27

David G. Stork

41,180
3
34
96

Thank you for you answer. Yes this is working, but what if I want to extract the elements in the list? HoldForm[foo] /@ {i}[[1]] won't work. – Vincent Wang Mar 18 '15 at 14:40
Well I also discovered HoldForm[foo]@i :) – Vincent Wang Mar 18 '15 at 14:50

Printing names of indexed variables instead of values

1 Answers1