Beginning C Programming Trivia Quiz

Answer: Kernighan & Ritchie

Kernighan & Ritchie published the industry standard manual in 1978. It is still published and used today and is a staple in a serious C programmer's library.

Answer: Spaces and tabs are both ignored.

Generally, whitespace (spaces, tabs, line feeds, returns) has no effect on the compiled code and beginning programmers should learn to use it liberally to make their code easier to read. As a player pointed out, the mere *presence* of whitespace can (but rarely) make a difference in some (rarely used) code constructs. For example:
i = a++ +b;
versus
i = a+ ++b;

Answer: They aren't used.

There are no line numbers used in writing C source code.

All "statement" lines end with a semicolon. Anything after the semicolon is really the start of the next line of code. So no numbers are needed to indicate a new line.

So this is legal:
i=3; j=5; k=i+j;

Line numbers ARE generally used by compilers to indicate locations of warnings or errors. The number, however, are NOT part of the C code proper.

Answer: Place the text between /* */ .

Comments are text preceded by /* and ended with */

For example:
/* This is a comment
This is still a comment */

Even though it's not part of the pure (ANSI) C standard, most modern C compilers accept a double slash (//) at the start of a line to indicate that the rest of the line is a comment. Programmers have adopted this readily.

// This IS a comment
This is NOT a comment;
// This IS another comment

Answer: Only "Hello World".

The comment opening combination /* (slash, asterisk) starts a comment until the comment closing combination */ (asterisk, slash).

So everything between those two symbols are comments and not compiled - even if several lines are traversed.

Answer: Sometimes there's a difference, sometimes not.

In the C language, the increment operator is ++ . The code i++ is the same as i = i + 1.

Further, i is incremented by one, regardless of which side the ++ operator is located. So, in most cases, the two constructs, i++ and ++i, are identical.

However, C allows you to construct some sophisticated code such as:
if( a > i++ )
in which case i is incremented AFTER its comparison with a.

Compare that to:
if( a > ++i ) ...
where i is incremented BEFORE the comparison.

It may seem elegant to take advantage of these types of subtle differences, but generally it's considered bad form to use constructs like either of these if statements as the original intention is likely not clear.

Answer: Nothing, and both versions are legal.

They are the same - remember that white space doesn't matter in C.

Answer: 8

The construct i *= 5 means the same as i = i * 5 (in other words, the new value of i equals the current value of i multiplied by 5).

Similarly, i += 3 means the same as i = i + 3.

Answer: if ( i != 0 )

The exclamation point, ! , is the negative operator.

Answer: 5

A common error in C programming is forgetting that the statements
if( i = 1 ) and if( i == 1 ) are vastly different.

The code i = 1, even within the confines of an if statement, is an assignment, making i equal to one. That assignment occurs before the 'if' part is tested. Since i now equals one, the if evaluates as true, forcing the statement j=3 to be run. So now j=3. Likewise, the following if statement will do the same thing, running j=5. So, at the end, j equals 5!

More likely, the code should have been written as:
j = 0;
i = 1;
if( i == 1 ) j = 3;
if( i == 2 ) j = 5;

Then j would equal 3 at the end, as probably intended.