Leading zero

[ajay pasi]

Hi statalist community,

* Example generated by -dataex-. For more info, type help dataex
clear
input  RTR
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
end

What I need, is to put leading zero in single digit number-

Needed output looks like.

RTR
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17

[Carlo Lazzaro]

Ajay:
I can figure the issue this way:

. tostring RTR, g(string_RTR)
string_RTR generated as str2

. g butler=0

. egen wanted=concat(butler RTR) if RTR<=9

. replace wanted= string_RTR if wanted==""

. keep wanted

. list

     +--------+
     | wanted |
     |--------|
  1. |     01 |
  2. |     02 |
  3. |     03 |
  4. |     04 |
  5. |     05 |
     |--------|
  6. |     06 |
  7. |     07 |
  8. |     08 |
  9. |     09 |
 10. |     10 |
     |--------|
 11. |     11 |
 12. |     12 |
 13. |     13 |
 14. |     14 |
 15. |     15 |
     |--------|
 16. |     16 |
 17. |     17 |
     +--------+

.

[Nick Cox]

If you want to see leading zeros in output but keep underlying values identical use format.

If you want a string with leading zeros for single digits, you can use strofreal() directly.

clear 
set obs 12 
gen have = _n 

format have %02.0f 

gen wanted = strofreal(have, "%02.0f")

list 

     +---------------+
     | have   wanted |
     |---------------|
  1. |   01       01 |
  2. |   02       02 |
  3. |   03       03 |
  4. |   04       04 |
  5. |   05       05 |
     |---------------|
  6. |   06       06 |
  7. |   07       07 |
  8. |   08       08 |
  9. |   09       09 |
 10. |   10       10 |
     |---------------|
 11. |   11       11 |
 12. |   12       12 |
     +---------------+

[ajay pasi]

Thank you Carlo and Nick.