How to replace spaces at the right into zeros at the left in COBOL?

Question

I have an alphanumeric variable with a length of 10. It contains a number at the beginning, the rest of the digits are filled with spaces. Then I need to move the string to the

Answer 1

I am surprised no one has suggested using NUMVAL here...

IDENTIFICATION DIVISION.
PROGRAM-ID. EXAMPLE.
DATA DIVISION.
WORKING-STORAGE SECTION.
01  VARIN     PIC X(10).
01  VAROUT    PIC 9(10).
PROCEDURE DIVISION.
    MOVE '123456    ' TO VARIN
    COMPUTE VAROUT = FUNCTION NUMVAL(VARIN)
    DISPLAY '>' VARIN '<'
    DISPLAY '>' VAROUT '<'
    GOBACK
    .

which produces...

>123456    <
>0000123456<

The problem with this approach is that if the NUMVAL argument does not convert to numeric the program throws an exception and dies. Also this is not very efficient from a CPU usage point of view because it requires character to binary numeric conversion and back to display format again (all done under the covers but takes cycles).

As a general rule I would not recommend using NUMVAL (even if it looks like a 'nicer' solution). I would stick with the solution as presented in the original question. That solution is computationally efficient and is a common idiom used in COOBL programming.