I am getting "Exception has occurred. Segmentation fault" in C-CodePudding

I am getting Segmentation error when i try to run this code.

#include <stdio.h>

int main() {
    int a = 0;

    printf("Enter a number");
    scanf("%d", a);
}

This is the error showing: enter image description here

I don't know what went wrong,

CodePudding user response：

You need to check how scanf is used at the document.

int scanf(const char *format, ...)

You have to pass the pointer of a

ref. https://www.tutorialspoint.com/c_standard_library/c_function_scanf.htm

CodePudding user response：

scanf takes a format string and a matching set of pointers. You haven't passed a pointer, but rather the value of a. In this case, that's 0.

Now, both of these are numeric types, so this does compile, but scanf attempts to dereference 0 and assign to it, which causes a segmentation fault.

This can be seen in a very simple program.

int main() {
    int a;

    *(int *)a = 42;

    return 0;
}