UNIT 02. BASICS OF PROGRAMMING IN C++ - Question And Answers - Computer Science For Class X

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Computer Science For Class X
Unit 02: Basics Of Programming In C++
Question And Answers

Q.1: Define Computer Program?
Ans: COMPUTER PROGRAM:
A computer program is a set of instructions that performs a specific task when executed by a computer. A computer requires programs to function and typically executes the program's instructions in a central processing unit. A computer program is usually written by a computer programmer in a programming language.

Q.2: Define syntax OR What is syntax in programming?
Ans: SYNTAX IN PROGRAMMING LANGUAGE:
Syntax refers to the rules that define the structure of a language. Syntax in computer programming means a set of keywords and characters that a computer can understand, interpret and perform task associated with them. The syntax of a language must be followed, and if it is not followed, the code will not be understood by a compiler or interpreter. Different programming languages have different types of syntax.

Q.3: Describe classification of programming language.
Ans: CLASSIFICATION OF PROGRAMMING LANGUAGE:
Based on the accessibility of hardware, programming languages can be classified into the following categories:

1. Low-level language
2. Middle-level language
3. High level language

Q.4: Define low level language.
Ans: LOW-LEVEL LANGUAGE:
Low-level programming languages are those languages that are directly communicated with computer hardware. The two languages come under this category are Machine language and Assembly language.

Q.5: Define machine language.
Ans: MACHINE-LEVEL LANGUAGE:
Machine language is a collection of binary digits or bits that the computer reads and interprets. This language is the only language understood by computers while machine language is almost impossible for humans to use because they consist entirely of numbers (0s & 1s). Machine code doesn't require translator because machine code is directly executed by computer. It is also called first generation language.

Q.6: Define assembly language.
Ans: ASSEMBLY LANGUAGE:
A program written in assembly language consists of a series of instructions called mnemonics that correspond to a stream of executable instructions. Assembly language code is translated by a translator called assembler. Assembly language uses keywords and symbols much like English and are easy to read, write and maintain as compared to machine language. It is also called second generation programming language.

Q.7: Define middle level language.
Ans: MIDDLE-LEVEL LANGUAGE:
The middle-level language lies in between the low level and high-level language. Middle-level language actually binds the gap between a machine level language and high-level languages, these languages are now become obsolete and are not in used.

Q.8: What do you know about high level language?
Ans: HIGH-LEVEL LANGUAGE:
High-level languages are relatively new and drastically revolutionized the programming world. It allows us to write computer code using instructions resembling everyday spoken language, usually English (for example: print, if, while). Programs written in a high-level language need to be translated by a translator (compiler or interpreter) into machine language before execution.

Q.9: write down the advantages or benefits of high-level language.
Ans: ADVANTAGES OF HIGH-LEVEL LANGUAGE:

• High level language is much closer to human language so it is more suitable to write code in high level language.
• It is more or less independent or portable of the particular type of computer used.
• It is easier to read, write and maintain.

Q.10: Write down the differences between low-level and high-level languages.
Ans: DIFFERENCES BETWEEN LOW-LEVEL LANGUAGE AND HIGH-LEVEL LANGUAGE:

Low Level Language	High Level Language
In low level language machine codes (0 and 1) are used as an instruction to the computer.	In high level language English like words are used as an instruction to the computer.
The execution of programs is quite fast.	The execution of programs is not very fast.
Instructions are directly understood by the CPU.	Instruction are not directly understood by the CPU.
No need to translate program. In case of assembly language assembler is required.	Translation of program is required.
The programs written in low level languages are machine dependent and are difficult to modify.	The programs written in high level languages are machine independent and are easy to modify.
The examples of low-level languages are: Machine language Assembly language	The examples of high-level languages are: BASIC, FORTRAN, COBOL, PASCAL, C languages etc.

Q.11: Define translators or language translators.
Ans: TRANSLATORS OR LANGUAGE TRANSLATORS:
Language translator is a computer program that converts high level language program into low level program (1s & 0s), or machine language. It transforms the source code into the object code (machine code) which understands directly by the computer processor. Translators also detect and report errors in the process of translation. There are three types of language translators.

• Interpreter
• Compiler
• Assembler

Q.12: What is compiler?
Ans: COMPILER:
Compiler is a program bat translates the high, level language program into machine language. Complier translates the whole Program at a time at once before it executed and makes a separate object file for the translated program. Translated program can he used multiple time without the need of retranslation of source code. Each high-level language has its own compiler.

Q.13: Define Interpreter?
Ans: INTERPRETER:
Interpreter is a language translator program, which converts high level program into machine language. It translates one instruction at a time. Interpreter does non make any object file and it translates the program every time when executed. An interpreter is faster than a compiler as It immediately executes the codes.

Q.14: Define Assembler.
Ans: ASSEMBLER:
An assembler is a translator that converts assembly language program iNto machine language. An assembler translates assembly language code directly Into machine code that can he understood by the CPU.

Q.15: Define source program or source code?
Ans: SOURCE PROGRAM /SOURCE CODE:
A Program or A program written by a programmer in any language other than machine language is called a source program or source code.

Q.16: Define object.
Ans: OBJECT PROGRAM /OBJECT CODE:
Object program is a program or code that is converted into machine language. (OR) The output from a language translator, which consists of machine language instructions, is called the object program.

Q.17: Write down the differences between interpreter and compiler?
Ans: DIFFERENCES BETWEEN INTERPRETER AND COMPILER:

Compiler	Interpreter
Interpreter translates high level language program into machine language line by line.	Compiler translates high level language program into machine language as a whole.
The interpreter translates the program every time when executed.	The compiler translates the program once at a time.
The interpreter does not make any object file.	The compiler makes a separate object file for the translated program.
Errors are displayed for every instruction interpreted if any.	Errors are displayed after entire program is checked.
Examples: BASIC, LISP etc.	Examples: C Compiler, C++ compiler etc.

Q.18: Define errors or programming errors.
Ans: ERROR:
An error describes any issue that arises unexpectedly that causes a program to not function properly. In general, there are three types of errors that occur in a computer program. Syntax Error, logical Error and Runtime Error.

Q.19: What Is syntax error?
Ans: SYNTAX ERROR:
A syntax error is an error in the syntax due to violation of rules of whatever language program is being written. These are sometimes caused by simple typing mistakes.

Q.20: What is logic error?
Ans: LOGIC ERROR:
In computer programming, a logic error is a bug or error in planning the program's logic. They do not cause the program to crash or simply not work at all, they cause it to 'misbehave' in some way, rendering wrong output of some kind. The computer does not tell us, what is wrong.

Q.21: What is runtime error?
Ans: RUNTIME ERROR:
A runtime error is a program error that occurs when a program is run on the computer and the result are not achieved due to some misinterpretation of a particular instruction. The code doesn't have any syntax or logic error but when it executes it cannot perform specific task.

Q.22: What is Programming Environment of C++?
Ans: PROGRAMMING ENVIRONMENT OF C++:
Programming environment is an environment which supports execution of programming language smoothly and efficiently on a local computer to compile and run programs.

Q.23: Define IDE or Integrated development environment?
Ans: INTEGRATED DEVELOPMENT ENVIRONMENT (IDE):
An integrated development environment (IDE) is software for building applications or programs that combines common developer tools into a single graphical user interface (GUI). IDE facilitates the development of applications designed to encompass all programming tasks in one application, one of the main benefits of an IDE is that they offer a central interface with all the tools, a developer needs. Dev-C++, is used for writing programs in C++ language, however there are many multiple language IDEs.

Q.24: Write down the benefits or advantages of integrated development environment.
Ans: BENEFITS / ADVANTAGES OF INTEGRATED DEVELOPMENT ENVIRONMENT:
IDE combines all tools that need for development. Programmers don't need to switch between different tools to design a layout, write the code, debug, build,etc.
Many IDEs incorporate basic spelling checkers, so automatically check for errors to improve code.
Libraries provide for functions in IDEs that are not included in the core part of the programming language.

Q.25: What are the components of Integrated Development Environment?
Ans: COMPONENTS OF INTEGRATED DEVELOPMENT ENVIRONMENT (IDE):
IDEs combining common tools that are necessary for a programmer to develop program, these are:
EDITING SOURCE CODE:
Writing and editing source codes is a major part of programming. A text editor is used for writing and editing source codes with feature providing language specific autocompletion, and checking for bugs as code is being written.

SYNTAX HIGHLIGHTING:
Syntax highlighting is a feature of IDEs that provides visual cues, keywords, and other words that have special meaning in languages are highlighted. This feature makes code easier to read or understand.

CODE COMPLETION:
It is a feature of IDE that completely knows the language syntax that speeds up process of coding by reducing typos and other mistakes. Autocompletion popups while typing, querying parameters of functions, query hints related to syntax errors.

COMPILER:
Compiler is a component of IDEs that translate source code into machine code. IDEs provide automated build process. This feature can help automate developer tasks that are more common to save time.

LINKER:
Linker connects or links referenced library files with compiled code. It saved the linked objects into an executable file.

LOADER:
This is the operating system's program that loads executable files into memory and directs the CPU to start running the program as directed by the IDE.

DEBUGGING:
The process of removing errors from a program is known as debugging. Debugging is a multistep process that involves identifying a problem, isolating the source of the problem. The final step of debugging is to test the correction or workaround and make sure it works.

Q.26: Define Linker, Loader and Debugging?
Ans: LINKER:
Linker connects or links referenced library files with compiled code. It saved the linked objects into an executable file.

LOADER:
This is the operating system's program that loads executable files into memory and directs the CPU to start running the program as directed by the IDE.

DEBUGGING:
The process of removing errors from a program is known as debugging. Debugging is a multistep process that involves identifying a problem, isolating the source of the problem. The final step of debugging is to test the correction or workaround and make sure it works.

Q.27: What do you know about Dev C++?
Ans: INTRODUCTION TO DEV-C++:
Dev-C++ is a fully featured graphical IDE (Integrated Development Environment) for programming in C / C++. DEV-C++ is developed by Bloodshed software. It was originally developed by Colin Laplace and first released in 1998. It is written in Delphi. With Dev C++ programmer can write Windows or console-based C/C++ programs easily.

Q.28: Write down the installation procedure of Dev C++:
Ans: INSTALLING AND CONFIGURING DEV-C++ IDE:
Dev-C++ is free available for download on Internet. After downloading the package begin the installation process. Following are the steps for installing Dec-C++ IDE.

STEP 1:

• Select "English" as the language to be used for installation process.

STEP 2:

• Press " I Agree" button to agree the license agreement.

STEP 3:

• Select "Full" from the drop-down menu "for type of Install". This will select all the necessary components required to run Dev-C++ and compile C++ source code.
• Click on "Next" to proceed.

STEP 4:

• Select the installation folder (directory) where all the necessary Dev-C++ files and libraries will be installed. Usually, the default specified path is used for installation but we can change it if desired.
• Click on "Install" to start installation.

STEP 5:

• After completing process, it will show a "Finish" dialog box.
• Make sure the "Run Dev-C++ 5..." is checked.
• Click 'Finish' button. This will automatically start Dev-C++ after installation completes.

CONFIGURING DEV-C++:

• Dev-C++ will require some configuration when it runs first time.
• Set "English (Original)". as default interface language in the Dev-C++ first time configuration dialogue.
• Click "Next" to continue.
• On the "Theme" selection dialog box leave the default setting and click on "Next" to continue.
• Click "OK' to close first time configuration dialogue.

LINKER SETTING FOR DEBUGGING:
Linker setting for bugging is required first time to obtain information about problems in source code. The following steps are used to enable this configuration.

• Click on Tools ➡ Compiler Options.
• Open the Setting tab from the Compiler Options dialogue box.
• Under Setting tab, open Linker tab.
• In Linker tab change the Generate Debugging Information (-g3) options to Yes.
• Click on OK to save setting.

Q.29: Write down the procedure to develop a program in Dev C++.
Ans: DEVELOPING PROGRAM IN DEV-C++:
Development of C++ program requires writing source and saving those files for compilation. The steps to create a new project in Dev-C++ are:

• Click on File ⇨ click New ⇨ Project.
• In New Project dialog, Select Empty Project.
• From language option, select C++ Project. Also enter Name for project.
• Click on OK.
• Dev C++ will ask path to save the new project, enter path and save project.

ADD NEW FILES TO PROJECT IN DEV-C++:
The step to create a new file are:

• Click on Project ⇨ New File. Alternatively we can also right-click on the Project Name in the Project Explorer and click on the New File.
• Click on Yes on the confirm dialog box to add a file.
• To save newly added file, click on File ⇨ Save. 
• Enter the path and provide its name.
• Click on Save to Store the file.

COMPILE AND EXECUTE PROJECT IN DEV-C++:
The steps to compile and execute project are:

• Project needs to compile before execution. To compile, click on Execute ⇨ Compile or press F9 key. Compiler Log tab shows the compilation status. Compiler tab will show if there are any syntax errors.
• After successfully compiling the project, run it by clicking on Execute ⇨ Run or by pressing F10 key.
• A console window will open and show the output of the program.

Q.30: What do you know about C++ programming language?
Ans: C++ PROGRAMMING LANGUAGE:
C++ is a powerful general-purpose programming language. It was created lay Bjarne Stroustrup in 1979 at Bell Laboratories. It is used to develop operating systems, browsers, games, and other applications. C++ mainly supports programming like object oriented. C++ is a flexible language aims to make writing programs easier and more pleasant for the individual programming.

Q.31: Define reserved words in C++.
Ans: RESERVED WORDS IN C++:
Reserved words are keywords that have standard predefined meanings in C++ language. These keywords can only be used for their intended purpose; they cannot be used as programmer defined identifiers.
The following list the keywords or reserved words of the C++ language:

and	new
asm	nullptr
auto	Operator
bool	Or
break	private
case	protected
catch	public
char	register
class	reinterpret_cast
const	requires
const_cast	return
continue	short
default	signed
delete	sizeof
do	static
double	static_cast
dynamic_cast	struct
else	switch
enum	template
explicit	this
export	Throw
extern	true
false	try
float	typedef
for	typeid
friend	typename
goto	union
if	unsigned
inline	Using
int	virtual
long	void
mutable	volatile
namespace	wchar_t
not	while

Q.32: Define data types in C++.
Ans: C++ DATA TYPES:
Data values passed in a program may be of different types. Each of these data types are represented differently within the computer's memory and have different memory requirements. These data types can be augmented by the use of data type qualifiers / modifiers.
The data types supported in C++ are described below:

Q.33: What ls constant? Also define its types.
Ans. CONSTANT:
A constant is an identifier whose value remains unchanged through out the program.

OR

Constants and Variables A constant is a data item whose value cannot change during the program's execution. Thus, as its name implies - the value is constant.

OR

A constant is a value that cannot be altered by the program during execution, i.e., the value is constant. When associated with an identifier, a constant is said to be "named," although the terms "constant" and "named constant" are often used interchangeably.

TYPES OF CONSTANT:
Constants are used in two ways. They are:

1. Literal Constants
2. Defined Constants

Q.34: Define literal constant.
Ans: LITERAL CONSTANT:
Literal constants are data used for representing fixed values. 'They can be used directly in the codes.
Example:

• 1, 2, 5, "c", "good" etc.

Q.35: Define symbolic constant.
Ans: DEFINED OR SYMBOLIC CONSTANT:
In C++, we can create symbolic constant whose value remains unchanged but used as a variable. A symbolic constant can be created using the #define preprocessor directive or const keyword.
Example:

• const int LIGHT_SPEED = 299792458;
• #define LIGHT SPEED 29972458

Q.36: Define variable and rules for naming variables.
Ans: VARIABLE:
A variable is nothing but a name given to a storage area that our programs can manipulate. Its value can change during program execution. Each variable C++ has a specified data type, which determine the size and layout of the variable's memory.

RULES FOR NAMING VARIABLE:
The general rules for constructing names for variables (unique identifiers) are:

• A variable name contains alphabets (letters), number, and underscores.
• A variable name must start with a letter or an underscore (_).
• Variable names are case sensitive. (myVar and myvar or Sum end sum are different variables)
• Variable names cannot contain whitespaces or special characters like !, #, % etc.
• Reserved words (Like C++ keyword, such as int cannot be used as names.
• A variable name cannot be longer than 32 characters in C++ by default.

Q.37: Define Declaring (Creating) and initializing Variables.
Ans: DECLARATION (CREATING) VARIABLE:
Variable declaration is a process in which we create storage space for variable in memory. A variable declaration consists of data type and name of the variable written as follow:

• data_type variable_name,
• int sum

INITIALIZATION:
Assign initial value to a variable is known as variable initialization. It can be initialized during declaration or separately. The equal sign is used to assign value written as follows:

• data_type variable_name value;
• int sum = 3;

Q.38: Define strings in C++.
Ans: STRINGS IN C ++:
Variables that can store alphanumeric value that consist of multiple characters are called strings. In C++, strings are used by one-dimensional array of characters, which is terminated by a null character \0.