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Service client C++ tutorial simple question

asked 2015-07-31 14:42:07 -0600

OmoNaija gravatar image

I have a question about the code:

if (
   ROS_INFO("Sum: %ld", (long int)srv.response.sum);
   ROS_ERROR("Failed to call service add_two_ints");
   return 1;

Why is there a return value of 1? Is a return value just always required when calling a service?

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You removed the function around your snippet, so we can only guess what the return value means. Is it the return value of your program?

NEngelhard gravatar image NEngelhard  ( 2015-08-01 04:33:14 -0600 )edit

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answered 2015-08-01 10:05:39 -0600

The return value of

Then the return value is always 1 (true - boolean) when the service succeeded in calling it. If for example the node for the service would have been stopped for any reason, the service would fail to call, because it does not exist, then you should get a 0 (false).

The return value of the else statement?

The return value of the else statement would be for your node or a function, anything else than 1 would indicate another process/calling function checking your programs/functions return and see if it is not 0 that something went wrong with it.

0 normally indicates, all right, sometimes it is the other way round ...

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Asked: 2015-07-31 14:42:07 -0600

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Last updated: Aug 01 '15