IBM Mainframe Forum

Hi, I have two questions
1. There is a technique in C, called bit field. Through this we can access bits. Is there anything like this in cobol?

Suppose I want to put an if condition based on the fourth byte of a field. If fourth byte contains 1 than set the flag and if fourth byte contains 0 than put some displays.

2. We have Union datastructure in C. Is there any datastructure like this in cobol?

Hello ajaygupta9 and welcome to the forums,

You mention "bits", then switch to "fourth byte". . .

If you mean 4th byte, you can use reference modification.

If you want some particular bit of a byte, i've always "decomposed" a byte into the component bits (using powers of 2). If you move the byte to a ws binary number and compare the number > 127, 63, 31, etc you can derive which bits are "on" and "off".

Hello again,

After replying, i noticed that your subject mentions a numeric field - i'd noticed that originally, but got caught up in the topic text and forgot about the number. . .

If i've not answered what you wanted to ask, please clarify the question.

Hi Dick,
Thanks for your reply.
My question is that, suppose a variable A contains some value, and now i want to put some condition based on the value in its fourth byte. How can I do that?

Please sugest me something on my second question also:-

2. We have Union datastructure in C. Is there any datastructure like this in cobol?

Hello,

As i mentioned before:

If you mean 4th byte, you can use reference modification.

Are you familiar with reference modification? Reference allows your code to "look at part of a field". If not, look here:
http://publibz.boulder.ibm.com/cgi-bin/ ... 10/1.7.1.8

I don't know how the "union datastructure" works. If you explain it clearly, i can tell you if there is a similar functon/process in cobol. My guess is that it is language specific.