Re: Operands are not compatible with the type of operator

The assignment operators are =. +=, -=, *=, ^=, and **= - in all of
them, the equal sign is last - don't know if a space would break them -
haven't even thought to try that!!. As you point out, the other
combinations are 2 separate operators - the assignment equal and a unary
operator.

You can't do the others in a reverse order - syntax error.

I believe the assignment compound operators came in around v5r2.

Vern

On 10/3/2010 4:23 PM, Douglas Handy wrote:

David,

I'm not 100% sure compound assignment operations are allowed in evals

... but regardless, try using "+=" instead of "=+" (although I'm not
sure it makes a difference).

It does make a difference. Consider:

x=+1;
x+=1;

The first sets x to positive 1; the second increments x by 1. Perhaps move
obvious:

x=-1;
x-=1;

The use of += over repeating the variable name (x+=1 vs x=x+1) seems to be a
personal coding style preference. When dealing with a very short variable
name (like x) then I don't much care because it is still obvious at a glance
the same variable name is mentioned on both sides of the equal sign. When
dealing with longer variables names, particularly cryptic names which don't
"read well", I prefer the += notation for the same reason I prefer to leave
Factor 1 blank in fixed format arithmetic. You don't have to examine the
names to make sure they are spelled exactly the same.

Ironically, long variable names which are "readable" are nearly as easy to
identify as being identical as very short names like x. The problem tends
more to be abbreviated field names from record formats or "legacy" code
converted to free format.

Doug