calculater-using-nesting-if-else.c

// We are going to code a calculater in our this program.
// let's start.
#include<stdio.h>
#include<stdlib.h> // We are goint to use exit function in this code so we
		   // connect this library.
void main()
{
   double number_1,number_2,result;
   char operaction;

	printf("Enter your Both Number  : ");
	scanf("%lf%lf",&number_1,&number_2);


        fflush(stdin); // this is use for flushing enter you pressed. affter
		       // entering number if we not use fflush then \n
		       // will store in operator and we got wrong result.
		       // It also comes in stdio.h library of C.

	printf("Please select a operaction from the given list :\n");
	printf("  +   for  addiction   \n");
	printf("  *   for  multiply    \n");
	printf("  -   for  subtruction \n");
	printf("  /   for  devide      \n");
        printf("  %%  for  remander    \n");// here we use %% because it display %
					    // on output.

	scanf("%c",&operaction);

	if ( operaction == '+' ) // or if ( operaction == 43 ) ASCII value of +
		result = number_1+number_2;
	else if ( operaction == '-' ) // or if ( operaction == 45 ) ASCII value of -
		result = number_1-number_2;
	else if ( operaction == '*' ) // or if ( operaction == 42 ) ASCII value of *
		result = number_1*number_2;
	else if ( operaction == '/'  ) // or if ( operaction == 47 ) ASCII value of /
		result = number_1/number_2;
	else if ( operaction == '%' ) // or if ( operaction == 37 ) ASCII value of %
        	result = (int)number_1%(int)number_2;
	else
		{
	        	printf(" INVALID OPERATOR ");
			exit(1);//It is a jump statement who close the program
				// we will discus about it later and we can
				// It use stdlib.h library of C.
				// write any number in ().There is no compulsion
				// to write 1 in it.
		}
	        printf("\n\n\n Your result is %.2lf.\n\n\n\n",result);
}