fopen() file handling function

fopen():-

C fopen is a C library function used to open an existing file or create a new file.It is compulsory to use for handling the file.

Syntax:-

It Contain two Parameters:-

1)filePath: The first argument is a pointer to a string containing the name of the file to be opened.
If the file is stored at some specific location, then we must mention the path at which the file is stored. For example, a file name can be like "any drive:// any folder/any file.txt".

2)mode: The second argument is an access mode,in which mode file is open.It is a string.

There are Different types of modes.

Note:- c open function return null in case of a failure.

EXAMPLE:-
(*) The above example will create a file called anyfile.txt.

(*)The w means that the file is being opened for writing, and if the file does not exist then the new file will be created.

Comments

Type casting

type casting or type conversion allows us to convert one data types into another.for type casting cast operator is required. Syntax:-- (type)expression or value; Example: int f =9/4; //without type casting o/p=2 float f=(float)9/4; //with type casting o/p=2.3 Type conversion are of two types: 1)Implicit Type Conversion:- it is also known as automatic type conversion.When the type conversion is performed automatically by the compiler,such type of conversion is known as implicit type conversion. 2)Explicit Type Conversion:- the type conversion performed by the programmer is known as explicit type conversion.which is done by cast operator as above mentioned.

CALL BY VALUE AND REFERENCE--

A function can be called by two types 1) Call By Value:- when an original value is not modified , is known as call by value. In call by value the actual parameter(the parameter passed to function) is copied into the formal parameter(parameter receive by function). in this the value of each variable in calling function is copied into the corresponding dummy variable of the called function. the changes made to the dummy variable have no effect on the actual variable. Example:- 2)Call By Reference:- when an original value is modified, is known as call by reference.in this a reference is used , denoted by &(symbol). we can use either pointer or reference for call by reference in this the address of the variable is passed into the function called by actual parameter. in this the memory allocation is same for both actual and formal arguments. Example:-

UNION

Definition:- Union is similar to structure, except it allows you to define the variable that share storage spaces.Defining a means creating a new data types. How use union:- when we create a structure by using struct keyword, now making a union we just replace the keyword struct with the keyword union , other syntax will be same. Difference between Structure and Union:- the only difference between them is in memory. NOTE:- union is used for low level programming but structure mostly used for high level programming. Program to access union:- """SHARE IT WITH YOUR FRIENDS IF HE DID NOT KNOW""""

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