Header files of c++ unit 3 -topic 3
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Header files contain function and variable definitions that are imported into C++ programs using the #include statement. Header files have a ".h" extension and declare functions and define macros. When a function is used in a C++ program, its definition must be imported from the library by including the appropriate header file. Common header files provide input/output operations (iostream.h), console input/output (conio.h), formatted I/O (iomanip.h), strings (string.h), mathematics functions (math.h), general purpose functions like memory management (stdlib.h), and random number generation (stdlib.h).
Header files of c++ unit 3 -topic 3
- 1. Header Files of C++ Header files contain definitions of Functions and Variables, which is imported or used into any C++ program by using the pre-processor #include statement. Header file have an extension ".h" which contains C++ function declaration and macro definition. Why need of header files When we want to use any function in our C++ program then first we need to import their definition from C++ library, for importing their declaration and definition we need to include header file in program by using #include.
- 2. Stdio.hInput and Output operations can also be performed in C++ using the C Standard Input and Output Library (cstdio, known as stdio.h in the C language). When you include iostream.h file in your program ,this file i.e, stdio.h automatically gets included in your program.
- 3. <iostream.h> • Standard Input / Output Streams Library. • Cin Standard input stream (object ) • Cout Standard output stream (object )
- 4. <conio.h> • conio.h header used in c programming contains functions for console input/output. • console is a term used for the black window, which is also called as command prompt. • Some of the most commonly used functions of conio.h are clrscr, getch,etc.
- 5. <iomanip.h> • This file declares services useful for performing formatted I/O with so-called parameterized stream manipulators, such as setw and setprecision. • setprecision -Sets the decimal precision to be used to format floating-point values on output operations. • Setw- Sets the field width to be used on output operations. • The operator used for taking the input is known as the extraction or get from operator (>>), while the operator used for displaying the output is known as the insertion or put to operator (<<).
- 8. Stringh.h
- 12. <math.h> • Most of the mathematical functions are defined in math.h ( cmath header in C++). • The functions that operate on integers, such as abs , labs , div , and ldiv , are instead defined in the stdlib.h header ( cstdlib header in C++).
- 15. <stdlib.h> • This header defines several general purpose functions, including dynamic memory management, random number generation, communication with the environment, integer arithmetics, searching, sorting and converting.
- 17. rand