Why do we need preprocessor directives in C++?

The preprocessors are the directives, which give instructions to the compiler to preprocess the information before actual compilation starts. You already have seen a #include directive in all the examples. This macro is used to include a header file into the source file.

Why and when do we use #define directive?

The #define directive is used to define values or macros that are used by the preprocessor to manipulate the program source code before it is compiled. Because preprocessor definitions are substituted before the compiler acts on the source code, any errors that are introduced by #define are difficult to trace.

What is meant by preprocessor directives?

Preprocessor directives are lines included in a program that begin with the character #, which make them different from a typical source code text. They are invoked by the compiler to process some programs before compilation.

What is a preprocessor directive explain them?

What is the meaning of preprocessor directive?

What does #include directive do?

The #include directive tells the C preprocessor to include the contents of the file specified in the input stream to the compiler and then continue with the rest of the original file.

What is the use of preprocessor directive in C programming?

The preprocessor will process directives that are inserted into the C source code. These directives allow additional actions to be taken on the C source code before it is compiled into object code. Directives are not part of the C language itself.

What is preprocessor directive explain #define and #include preprocessor directives?

Last updated: January 12, 2018.

What do you understand by preprocessor directive?

What will the preprocessor DO for a program?

Inclusion of header files. These are files of declarations that can be substituted into your program.

Macro expansion. You can define macros,which are abbreviations for arbitrary fragments of C code,and then the C preprocessor will replace the macros with their definitions throughout the program.

Conditional compilation.

Line control.

What is preprocessor what are the advantages of preprocessor?

A preprocessor is a language that takes as input a text file written using some programming language syntax and output another text file following the syntax of another programming language. Advantages of preprocessor are that it makes- 1) the program easier to develop. 2) easier to read. 3) easier to modify.

What is pre-processor directive do?

A program which processes the source code before it passes through the compiler is known as preprocessor.

The commands of the preprocessor are known as preprocessor directives.

It is placed before the main ().

It begins with a#symbol.

They are never terminated with a semicolon.

What does the preprocessor DO?

In computer science, a preprocessor is a program that processes its input data to produce output that is used as input to another program. The output is said to be a preprocessed form of the input data, which is often used by some subsequent programs like compilers.