C/Macro Preprocessor/Macro Constant
Содержание
- 1 Define constant in Macro
- 2 Define constant in Macro for loop control
- 3 Define header file name in macro
- 4 Define Macro and use it as the loop condition
- 5 Define macro: constant
- 6 Define macro for string and output
- 7 Define macro inside the main function
- 8 Define Macro: TRUE and FAlSE
- 9 Define marco based calculation
- 10 Use Macro
Define constant in Macro
#include <stdio.h>
#include <assert.h>
#define ROW_Constant 10
#define COL_Constant 10
int main() {
int row, col;
for ( row = 1; row <= ROW_Constant; row++) {
assert ( row <= ROW_Constant );
for ( col = 1; col <= COL_Constant; col++ ) {
assert ( col <= COL_Constant );
printf ( "%4d", row * col );
}
printf ( "\n" );
}
}
Define constant in Macro for loop control
#include <stdio.h>
#define count 31
int main() {
int heat[count];
int i;
float celsius;
for(i = 0; i < count; i++) {
celsius = ( 5.0 / 9.0 ) * ( heat[ i ] - 32);
printf("%d \t \t%6.2f \n", heat[ i ], celsius);
}
}
Define header file name in macro
#define STDIO <stdio.h>
#include STDIO
int main(void)
{
printf("This is a test.");
return 0;
}
Define Macro and use it as the loop condition
#include <stdio.h>
#define MAX 100
int main(void)
{
int i;
for( i = 0; i < MAX; i++)
printf("%d ", i);
return 0;
}
Define macro: constant
/* Define macro */
#include <stdio.h>
#define PI 3.14159f /* Definition of the symbol PI */
void main()
{
float radius = 0.0f;
float diameter = 2.0f;
float circumference = 0.0f;
float area = 0.0f;
radius = diameter/2.0f;
circumference = 2.0f*PI*radius;
area = PI*radius*radius;
printf("\nThe circumference is %.2f", circumference);
printf("\nThe area is %.2f", area);
}
Define macro for string and output
#include <stdio.h>
#define FUN "Macro Substitutions"
int main(void)
{
printf(FUN);
return 0;
}
Define macro inside the main function
#include <stdio.h>
void f(void);
int main(void)
{
#define LIGHTSPEED 186000
f();
return 0;
}
void f(void)
{
printf("%ld", LIGHTSPEED);
}
Define Macro: TRUE and FAlSE
#include <stdio.h> /* For input and output */
#define TRUE 1 /* Defines the symbol TRUE */
#define FALSE 0 /* Defines the symbol False */
void main()
{
int correct = TRUE; /* By default indicates correct sequence entered */
printf("%s\n", correct? "Correct!" : "Wrong!");
}
Define marco based calculation
#include <stdio.h>
#define SMALL 1
#define MEDIUM SMALL+1
#define LARGE MEDIUM+1
int main(void)
{
printf("%d %d %d", SMALL, MEDIUM, LARGE);
return 0;
}
Use Macro
#define BIG_NUMBER 10 * 10
main()
{
int index = 0;
while (index < BIG_NUMBER) {
index = index * 8;
}
return (0);
}