What is constants ? | Difference between constant and variable | How we define a constant ?
What is constant? The constants are the quantity whose value can’t be change or modified during the execution of the program. The concept of constants is same as the variable but the value of constant can’t be over write as variable. The constant must be defined before use and as variable it can't be define by cin . We must define it by a prescribe method. Defining Constants: There are two simple ways in C++ to define constants: Using #define preprocessor. Using const keyword. The #define Preprocessor: Following is the forms to use #define preprocessor to define a constant: #define identifier value Following example explains it in detail: #include <iostream> using namespace std; #define LENGTH 10 // a constant define #define WIDTH 5 // a constant define #define NEWLINE '\n' //constant define for new line void main( void ) { int area; area = LE...