Compile Conditional Field Article For Free

Conditional compilation is controlled by $IF , $ELSE , and $END constructs, which behave in a similar way to the COBOL IF construct. Conditional compilation also supplies the $DISPLAY Statement, which can be used to display a message during compilation or include a version number in the object file.

It is a pre-process of execution of a program using c/c++ language. To initialize a process of preprocessor commands, it's mandated to define with a hash symbol (#). It can preferably be the non-blank character, and for better readability, a preprocessor directive should start in the first column.

Conditional compilation provides a way of including or omitting selected lines of source code depending on the values of literals specified by the DEFINE directive. In this way, you can create multiple variants of the same program without the need to maintain separate source streams.

Syntax of Conditional Inclusion Statements #if , #else , #elif , #ifdef , #ifndef , and #endif are the most commonly used conditional compilation directives. These directives allow us to conditionally include portions of code based upon the outcome of a constant expression.

Conditional Compilation: Conditional Compilation directives help to compile a specific portion of the program or let us skip compilation of some specific part of the program based on some conditions. In our previous article, we have discussed about two such directives 'ifdef' and 'endif'.

In computer programming, conditional compilation is a compilation technique which results in an executable program that is able to be altered by changing specified parameters.

The #define directive can be used to create a name for a numerical, character, or string constant, whereas a const object of any type can be declared. A const object is subject to the scoping rules for variables, whereas a constant created using #define is not.