Reads and writes functions

Question

To accumulate or recover data in binary form, the member functions write () or read () can be utilized. Unlike put () and get (), the write () and read () functions access data in binary arrangement. In binary format, the data representation in the system and in the file is similar. The number of bytes required to represent an integer in text from is proportional to its magnitude, where as in binary form the size is always fixed irrespective to its magnitude. Thus the binary form is more accurate, and provides faster access to the file because no conversion is required while performing read or writes. The read () and write () functions have the subsequent syntax: -

In file. Read ((char *) & variable, size of (variable));

Out file. Write ((char *) & variable, size of (variable));

The first parameter is a pointer to a memory location at which the data retrieved from the file is to be stored in case of read () and address at which data is to be written when retrieved from a file in case of write (). The second parameter indicates the number of bytes to be transferred and the programme give below illustrates the certain and manipulation of binary files.

Use of write and read member of file steams:

# include < f stream. h >

   Void main ()

{

Int num 1 = 530;

Float num 2 = 1050.25;

// open file in write binary mode, write integer and close.

Of stream out _ file (num. Binary", ios : : binary);

 Out _ file. Write ((char *) & num 1, size of (num 1));

 Out _ file. Write ((char *) & num 2, size of (num 2));

Out _ file. Close ();

If stream in _ file ("number. Binary", ios : : binary);

In _ file. Read ((char *) & num 1, size of Int));

In _ file. Read ((char *) & num 1, size of (num 2));

  Cout << num 1 << " " << num 2 << end 1;

In _ file . close ();

}