New with CS, and new with C language. Please help with the program needs to support all +, -, *, /, % functions and return the user input equation's result. The program should be continuously accepting new input until the user enters a blank line. and shouldn't print any output except for the equation's result.
e.g. input and output:
8 + 2 (enter) - user input
10 - output
8 - 2 (enter) - user input
6 - output
(enter) - user input(program terminates)
the hint was provided are use gets() & sscanf() to take input from user.
#include <stdio.h>
int main()
{
char equation[10];
int x, y, result;
char eqsign[2];
int switchnum;
gets(equation);
sscanf(equation, "%d %s %d", &x, eqsign, &y);
if (eqsign == '+')
switchnum = 0;
else if (eqsign == '-')
switchnum = 1;
else if (eqsign == '*')
switchnum = 2;
else if (eqsign == '/')
switchnum = 3;
else if (eqsign == '%')
switchnum = 4;
while(equation != "\0")
{
switch(switchnum)
case '0':
result = x + y;
printf("%d", result);
break;
case '1':
result = x - y;
printf("%d", result);
break;
case '2':
result = x * y;
printf("%d", result);
break;
case '3':
result = x / y;
printf("%d", result);
break;
case '4':
result = x % y;
printf("%d", result);
break;
}
return 0;
}
The code I have now is not running correctly, please provide any suggestions with C! Having a lot of problems on how to compare the operator form input. Any help would be appreciated!
Since the operator is a single character, there is no need to make a string of it. Also, there is no need for switchnum, as you can switch directly on the operator value.
#include <stdio.h>
int main()
{
char equation[22];
int x, y, result;
char operator;
if (!fgets(equation,sizeof(equation),stdin)) {
perror("Reading equation");
return -1;
}
if (sscanf(equation, "%d %c %d", &x, &operator, &y) != 3) {
fprintf(stderr,"Invalid equation!\n");
return -2;
}
switch(operator) {
case '+':
result = x + y;
break;
case '-':
result = x - y;
break;
case '*':
result = x * y;
break;
case '/':
result = x / y;
break;
case '%':
result = x % y;
break;
default:
fprintf(stderr,"Invalid operator '%c'!\n",operator);
return -3;
}
printf("%d", result);
return 0;
}