Notes

int arr[5]={1,2,3,4};
char str[10]=
char=1
float,int=4
total no of elements in array=sizeof(a)/sizeof(int)
scanf reads until it encounters space newline tab
gets() function allow to read a string containing spaces from user.
puts() function allow to print a string containing spaces.
diff bw gets() and fgets()
gets() will read all charectars entered irrespective of size while fgets() function allows to reads a specified number of characters.
Syntax:
fgets(string_name, sizeof(string_name), stdin);
int atoi(str)-ascii to int value


Pointer is a variable that holds the address of another variable.
datatype *variable_name; or
datatype* variable_name;
%p is a format specifier which is used for displaying the address in hexadecimal.
malloc()
Stands for memory allocation.
Allocates block of memory of specified type and return a pointer of type void which can be casted into any type of pointer. It leaves the memory uninitialized.
calloc()
Stands for contiguous allocation.
Allocates contiguous memory and return a pointer to the memory. It initializes all allocated bytes to zero.
Note: Dynamically allocated memory created with either malloc() or calloc() doesn't get freed
on their own.
free()
Free previously allocated memory
realloc()
Alters the size of previously allocated memory
STRUCTURES AND UNIONS
A union is a special data type available in C that allows to store different data types in the
same memory location.

You can define a union with many members, but only one member can contain a value at
any given time i.e. on shared memory, any fresh data replaces any existing data.
Union provide an efficient way of using the same memory location for multiple-purpose
Both structure and unions are used to group a number of different variables together. Syntactically both structure and unions are exactly same.
The main difference between them is in memory storage.
In structures, each member has its own memory location but all members of union use the same memory location which is equal to the greatest member’s size.
topics left
lab assignment 6,8,9
est 3 papers
1)revise arrays strings pointers and control structures file handling
2)arrays programs