C 中的堆栈括号匹配

Question

When I execute this code and debug, I see the "h" between op1 and op2 values when I entered two parentheses () . I don't know where it came from. Can you help me to solve this problem? It's about data structure without pointers. I don't know where this garbage value comes from.

Problems:

op = pop();
printf("op1: %ch\n", op); //() = h
op2 = ch;
printf("op2: %ch\n", op2);   

Link below which has full of code. https://paste2.org/yNhFcx5s

Answer 1

The format specifier for char is %c. the extra h added by you is being printed

Answer 2

If op and op2 have type short int , the correct code would be:

op = pop();
printf("op1: %hc\n", op);
op2 = ch;
printf("op2: %hc\n", op2);

and since the type is actually char , you might even write:

op = pop();
printf("op1: %hhc\n", op);
op2 = ch;
printf("op2: %hhc\n", op2);

But you could just use %c as short and char values are promoted to int when passed to variadic functions such as printf() .