Fbise Notes-Computer | Programming in C Chapter no.02 class 10th

 Programming in C

Extensive Questions

 

Q.No1 Describe the following HLLs.

Ans:   C:

C was developed in early 1970s by Dennis Ritchie at Bell Laboratories. It has become one of the most popular programming language today. It is highly structured easy  to understand and use. In past it was only used to write O.S, compiler assembler etc. today , it is used to write all types of application programs word-processing, spreadsheet program DBMS etc.

            C++:

C++ was developed by Bjarne Stroustrup also at Bell Laboratories during 1983-85. It is superset of C, any valid C program is also a C++ program. C++ provide programming facilities to easily and quickly write more powerful programs.

Visual Basic:

Visual Basic is evolved from the easier version called BASIC. VB is very popular programming language for writing windows and web applications. It is also used to developed business programs such as payroll system, inventory control system. VB is also used to write programs related with engineering, science, arts, education, games.

C#:

C sharp is developed in 2000 by Microsoft Corporation. It is simple, modern, general purpose programming language. Syntax of C# is similar to C and C++. It has some features of Java. It is used to write web applications. All types of programs  like game, utilities, O.S, compiler and business Apps can also be developed using C#.

Java:

Java is high level language developed by Sun Microsystems. It is similar to C and C++. It is used to write small programs that can be embedded in a web page accessed through internet. It is ideal for network computing. It is used for writing programs for wide range of devices like computers and networks. Most of the web browsers are made java enabled, like internet explorer and Firefox etc.

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  Q.No2   Differentiate between Compiler and Interpreter.

  Ans:  Compiler:

It is computer software that translates source program into object program. Source program consists of statements written in HLLs. The source program is translated with a compiler into machine language, the resulting program is known as object program. The object program is understandable by machine but not by human.

Interpreter:

Interpreter translates HLL program into machine language but it translates one instruction at a time and executes it immediately before translating the next instruction. Its speed of translating is slow than a compiler. Examples of programming languages that use interpreter are Java Script, BASIC, VB and Perl.

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  Q.No.3 Describe the function of linker and loader programs.

    Ans:  Linker:

Linker is the software that translates object program into a single executable program. During this process, if it could not find definition of a particular function that is used in the program, then it would assume that it is defined in C library. It will replace this function in the object program with the code from C library and then creates a single executable program.

           

            Loader:

        It is a software that loads programs into memory and then executes them.      

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  Q.No.4 What are the rules for specifying a variable name in C language?

 

Ans:     The following are the rules for specifying variable names in C language.

i.                    A variable begins with a letter or underscore( _ ). over_time.

ii.                  Both upper and lower case letter are allowed for naming variables.

iii.                Special characters cannot be used as variable name e.g., #, ?, @ etc.

iv.                Reserved words of C cannot be used int, case, if etc.

v.                  There must be no embedded blank in the name of a variable  ma ss is not correct.

        

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 Q.No.5  What is the difference between implicit type casting and explicit                                type casting?  Give examples.

           

                

 Ans:     Implicit Typecasting:

Implicit typecasting is performed automatically by the compiler without programmer’s intervention. It converts all operands  into the data type of the largest operand. Suppose an expression contains variables of integer and double data types the result will be evaluated to a double data type.

            Example:

                        #include <stdio.h>

void main(void)          

{

            float value1 = 2.5

            float value2 = 5.3;

            int result;

              result = value1 + value2;

            printf(“Result : %d”,result);

}

   Explicit Typecasting:

Explicit casting is performed by programmer. He defines the data type in parenthsis before the variable or expression.

                        Example:

                        #include <stdio.h>

void main(void)          

{

            int value1 = 30

            int value2 = 7;

            float result;

            result = (float)value1 / value2;

            printf(“Result : %f”,result);

}                     

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Q.No.6  What is a preprocessor? Give examples.

Ans:     Preprocessor Directives:

These are instructions for the C compiler. Every C program contains preprocessor directives at the beginning of the program. These directives start with sign (#). The most commonly used preprocessors are include and define.

The include Preprocessor:

            It has the following syntax.

#include <header file name>

When the preprocessor is carried out by C compiler, it will search for the header file htat is written within the less and greater than symbols and copy it in the source file. The header file used here is stdio.h. it includes printf() and scanf() function prototypes.

The define Preprocessor:

            It is used for defining constants in C program. It gives meaningful name to constant value that is to be used in the program.

It has the following syntax.

#define SYMBOL value/expression

For example #define HEIGHT 12

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