The break statement exits the current loop block, while the continue statement skips the rest of the current loop iteration and continues with the next iteration. Union allocates memory equal to the maximum size of its members and shares the memory, while structure allocates memory equal to the total size of its members and each member has its own space. A self-referential structure is one that contains a reference to itself, like a linked list node containing a pointer to the next node. Binary files contain custom data represented as bits, while text files contain characters represented as bits.

1. What is the difference between break & continue?
The break statement will immediately jump to the end of the current block of
code.
The continue statement will skip the rest of the code in the current loop block and
will return to the evaluation part of the loop.
break will exit the loop completely, but continue will just stop the current iteration.
i.e. Continue will skip the rest of the code and goes for another iteration in the
loop.
What is the difference between structure & union?
1. Union allocates the memory equal to the maximum memory required by the
member of the union but structure allocates the memory equal to the total
memory required by the members.
2.
In union, one block is used by all the member of the union but in case of
structure, each member has their own memory space.
3.
Union is best in the environment where memory is less as it shares the memory
allocated. But structure can not implement in shared memory.
4.
As memory is shared, ambiguities are more in union, but less in structure.
5. Self referential union cannot be implemented in any datastructure, but self
referential structure can be implemented.
What is self referential structure?
It is exactly what it sounds like: a structure which contains a reference to itself. A common
occurrence of this is in a structure which describes a node for a linked list. Each node needs a
reference to the next node in the chain.
struct linked_list_node {
int data;
struct linked_list_node *next; // <- self reference
};

2. A self-referential structure is a data structure that includes references to other data of its same
type. A simple example of this would be an implementation in C of a linked list:
typedef struct listnode {
void *data;
struct listnode *next;
} list_t;
The reference to a listnode struct from within a listnode struct is the self-referential aspect of
the structure.
Q: What is the difference between binary and text files?
While both binary and text files contain data stored as a series of bits
(binary values of 1s and 0s), the bits in text files represent characters,
while the bits in binary files represent custom data. While text files
contain only textual data, binary files may contain both textual and
custom binary data.
Mode Description
r
Opens an existing text file for reading purpose.
w
Opens a text file for writing, if it does not exist then a new file is created. Here your program will
start writing content from the beginning of the file.
a
Opens a text file for writing in appending mode, if it does not exist then a new file is created.
Here your program will start appending content in the existing file content.
r+
Opens a text file for reading and writing both.
w+
Opens a text file for reading and writing both. It first truncate the file to zero length if it exists
otherwise create the file if it does not exist.
a+
Opens a text file for reading and writing both. It creates the file if it does not exist. The reading
will start from the beginning but writing can only be appended.