C C++ Interview Question. Question 1

When should you use "do while" in C macro ?
 
One cool thing I learned about C macro on Quora was about using

do while

in macro which are multiple statement.

for example if we have this macro:

1 2 3

#define macro1 line1;\ line 2;\ line3;

if we use this macro in our code like this:

1 2	if (condition) macro1

then in that case

line2

and

line3

are executed always irrespective of

condition

, which was not the original intention.

so we should have the macro like this instead:

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#define macro1 do { line1;\ line 2;\ line3; } while(0);