Why Do I Get Segmentation Fault For The Below Code?

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typedef struct {
int a;
int c;
}s1;

typedef struct {
int b;
}s2;

typedef const struct {
s1 *ptr1;
s2 *ptr2;
}M;
static M stinstance;
void main()
{
stinstance.ptr1->a = 10;
printf("%x",stinstance.ptr1);
}

Posted 7-Apr-15 18:39pm

Member 11589155

Updated 7-Apr-15 19:26pm

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barneyman · Accepted Answer · 2015-04-07T19:21:00

Solution 1

Because the members ptr1 and ptr2 of M are pointers, that haven't been initialised - so they currently contain random values

pointers are addresses to things - those things need to be allocated, or already existing, before their address can be used

A Beginner's Guide to Pointers[^]

Posted 7-Apr-15 19:21pm

barneyman