Check wrong input and stuck in infinite loop (C)-CodePudding

I cannot use string or char input. If I use input like "c" then

int x,y,z;
while (1)
{
    z=scanf("%d%d", &x,&y);
    if(z == 0){
        printf("correct!\n");
    }
    else{
        printf("Incorrect!\n");
    }
}

CodePudding user response：

Check properly against success, not 0.

On failure, consume characters until end-of line. If scanf("%c", ...) or the like not allowed due to "I cannot use string or char input.", you are out of luck.

Exit the loop on success or end-of-file

do {
  z = scanf("%d%d", &x,&y);
  //if(z == 0){
  if (z == 2) {
    printf("correct!\n");`
  } else if (z != EOF) {
    printf("Incorrect!\n");
    char ch;
    while ( scanf("%c", &ch) == 1 && ch != '\n') {
      ;
    }
  }
} while (z != 2 && z != EOF);

CodePudding user response：

I don't know what exactly you are looking for. I also don't know exactly what this code does, but if you want to stop the infinite loop, hope this helps.

#include <stdio.h>
 
int main () {
   int x,y,z;
    while (1) {
        z = scanf("%d%d", &x,&y);
        if(z == 0) {
            printf("correct!\n");
            break;
        } else {
            printf("Incorrect!\n");
        }
    }
}