I am the beginners of programming so,i don't know the use flag in c.since ,i have searched many question about flag in c but i don't get it.i request you to answer my question to you developers thank you.
12 Answers
A "flag" variable is simply a boolean variable whose contents is "true" or "false".
You can use either the bool type with true or false, or an integer variable with zero for "false" and non-zero for "true".
So why would you use a flag?
Suppose you are outputting a byte value in binary, one bit at a time, say decimal 42 which is 00101010.
But, you don't want any leading zeros, and the output should be 1010101.
You can use a flag to tell you whether to suppress the 0 bits. Start with the flag as true, and whenever you output a 1 bit you set the flag to false, telling you not to suppress 0 bits any more.
Of course, the final bit needs to be output even if all bits are 0, but that's another matter.
