Remember to initialize the pointer

Tag: Address error RoCE turned test program initial highlight

Today, in the writing sequence stack, the beginning of the formal parameter is passed through the address, that is, with Seqstack &s Pass, and then see the online useful pointers to pass, so want to change to use the pointer to pass.

Problem came, when I put all the S.top s.data modified to S->top s->data, Seqstack &s modified to Seqstack *s run, with the codeblocks, the operation is not error, but do not print out the elements in the stack, Run one to return to Process returned-1073741819 (0xC0000005) error exit. In order to find the exact location of the error, I added printf () to find the problem, that is, as long as the run to have s->top or s->data to exit unexpectedly. Because the stack is to be initialized, execution to S->top =-1 o'clock in Initstack (Seqstack *s) exits unexpectedly.

What's the problem? So I wrote a simple test procedure in my writing.

#include <stdio.h>typedef int datatype;typedef struct{    DataType data;    int top;} Seqstack;int Main () {    seqstack *s;    Remove the annotation program for normal operation output 1   //seqstack address;   S = &address;    S->data=;    S->top = 1;    printf ("%d%d", S->data, S->top);}

The problem is that there is no pointer to the definition being initialized. How do you judge if a pointer is not initialized?

The following is the author's idea, in Codeblocks run the exit returned is the process returned-1073741819 (0xC0000005), then the other, then wrote a program to test.

#include <stdio.h>int main () {    int *a, B;    b = +;    A = &b;    printf ("%d", *a);}

After running, the same is returned error Process returned-1073741819 (0xC0000005), then there will be no wild pointer, there is this error AH. The author Baidu A bit, found that this error is related to memory, then the wild pointer is not pointing to a deleted object or not requesting access to restricted memory area.

So this error is related to memory, so when this problem occurs, it is advisable to check the memory-related statements.

Of course, it's important to have a good programming habit!!! When defining pointers, be sure to initialize, the default value of the wild pointer is random, it will randomly point to a pass, regardless of whether the address is legitimate, so the operation of the wild pointer can easily cause a program error!!

　　

Remember to initialize the pointer