Malloc memory circuit
Hi i have below code to create linked list
#include<stdio.h>
#include<stdlib.h>
struct node{
unsigned int data1;
unsigned int data2;
struct node *ptr;
}obj;
void enterData() // Here the EnterDAta fnnction uses the obj object to enter the data and note that this
{ // obj is used agauin and again in the every node of the list to enter the data
printf("\n Enter the data1 ");
scanf("%u",&obj.data1);
printf("\n Enter the data2 ");
scanf("%u",&obj.data2);
}
void append(struct node **start) // This is used to append the dara un the list or also used to add the first element in the list
{
enterData();
struct node *next_node=*start;
if(next_node==NULL)
{
printf("\nAdding first element in the list ......\n");
next_node=malloc(sizeof(struct node));
printf("\n The memory location of next_node is %p",&next_node);
if(next_node==NULL)
{
printf("\n Out of Memory");
}
else{
next_node->data1=obj.data1;
printf("\n The memory location of next_node->data1 is %p",&next_node->data1);
next_node->data2=obj.data2;
printf("\n The memory location of next_node->data2 is %p",&next_node->data2);
next_node->ptr=NULL;
*start=next_node; //This line of code here is modifying the header pointer see the magic of the pointer :)
}
printf("\n The first element added successfully");
}
else
{
printf("\n Appending the data ......\n");
struct node *temp=next_node;
next_node=malloc(sizeof(struct node));
if(next_node==NULL)
printf("\n Out of Memory");
else
{
next_node->data1=obj.data1;
next_node->data2=obj.data2;
next_node->ptr=NULL;
while(temp->ptr!=NULL)
temp=temp->ptr;
}
temp->ptr=next_node;
temp=NULL;
printf("\n Data appended Successfully!!! ");
}
next_node=NULL;
}
int main()
{
struct node *head=NULL;
append(&head);
return 0;
}
In the above code, tell me if I get the memory address next_node as 1000
, then the memory address I get for next_node->data1 is 1000
and the memory addressnext_node->data2 is 1004
But if in the above append function, if just change some changes in the code like this
void append(struct node **start) // This is used to append the dara un the list or also used to add the first element in the list
{
enterData();
struct node *next_node=*start;
if(next_node==NULL)
{
printf("\nAdding first element in the list ......\n");
next_node=malloc(sizeof(struct node));
if(next_node==NULL)
{
printf("\n Out of Memory");
}
else{
next_node->data2=obj.data2;
printf("\n The memory address of next_node->data2 is %p ",&next_node->data2);
next_node->data1=obj.data1;
printf("\n The memory address of next_node->data1 is %p ",&next_node->data1);
next_node->ptr=NULL;
*start=next_node; //This line of code here is modifying the header pointer see the magic of the pointer :)
}
printf("\n The first element added successfully");
}
else
{
printf("\n Appending the data ......\n");
struct node *temp=next_node;
next_node=malloc(sizeof(struct node));
printf("\n The memory address of next_node is %p ",&next_node);
if(next_node==NULL)
printf("\n Out of Memory");
else
{
next_node->data1=obj.data1;
next_node->data2=obj.data2;
next_node->ptr=NULL;
while(temp->ptr!=NULL)
temp=temp->ptr;
}
temp->ptr=next_node;
temp=NULL;
printf("\n Data appended Successfully!!! ");
}
Now if the address next_node is 2000
then I get the memory address next_node->data1 as 2004
and for data2 is 2008
, butshouldn't it be the other way as we are first storing the data2 in the memory location using the next_node pointer ?
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The relative addresses of the members of your nodes are a function of the layout struct node
, not the order in which you refer to them. If you change the members data1
and data2
in the ad struct node
, you'll see that data2
appears at the bottom address in each instance, but with the current ad data1
will appear first in each instance.
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