why do i get 6 from default statement if my input was another character other than (+, -, *, /)

Question

#include <stdio.h>
int calculator(int num1,int num2, char p)
{
    switch(p)
    {
        case '+':
            return num1+num2;
        case '-':
            return num1-num2;
        case '*':
            return num1*num2;
        case '/':
            return num1/num2;
        default:
            printf("Error\n");
            break;
    }
}

int main()
{
    int num1,num2,answer=0;
    char p;
    while(1)
    {
        answer=0;
        printf("Enter 2 numbers\n");
        scanf("%d%d",&num1,&num2);
        printf("Enter the operator\n");
        scanf(" %c",&p);
        answer=calculator(num1,num2,p);
        printf("the answer is %d\n",answer);
    }
    return 0;
}

I get 6 every time the default statement is executed no matter the input this is my input ( Enter 2 numbers first number 4 second number 8 Enter the operator operator H ) the output ( Error the answer is 6 )

Answer 1

Your calculator function doesn't execute a return for the break fallthrough case. Strictly speaking this is undefined behavior. See Why and how does GCC compile a function with a missing return statement?