The C Preprocessor Versus the Compiler
One important thing you need to remember is that the C preprocessor is not part of the C compiler.
The C preprocessor uses a different syntax. All directives in the C preprocessor begin with a pound sign (#). In other words, the pound sign denotes the beginning of a preprocessor directive, and it must be the first nonspace character on the line.
The C preprocessor is line oriented. Each macro statement ends with a newline character, not a semicolon. (Only C statements end with semicolons.) One of the most common mistakes made by the programmer is to place a semicolon at the end of a macro statement. Fortunately, many C compilers can catch such errors.
The following sections describe some of the most frequently used directives, such as
TIP
Macro names, especially those that will be substituted with constants, are normally represented with uppercase letters so that they can be distinguished from other variable names in the program.
The C Preprocessor Versus the Compiler
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The if statement
The if statement
If life were a straight line, it would be very boring. The same thing is true for programming. It would be too dull if the statements in your program could only be executed in the order in which they appear.
Mathematical Functions in C
Mathematical Functions in C
Basically, the math functions provided by the C language can be classified into three groups:
Trigonometric and hyperbolic functions, such as acos(), cos(), and cosh().
Changing Data Sizes
Changing Data Sizes
Enabling or Disabling the Sign Bit
Enabling or Disabling the Sign Bit
As you know, it's very easy to express a negative number in decimal. All you need to do is put a minus sign in front of the absolute value of the number. But how does the computer represent a negative number in the binary format?
Question and Answer
Question and Answer
Q Which bit can be used as the sign bit in an integer?