Computer programming questions
- 1. COMPUTER PROGRAMMING QUESTIONS 1) What is C language? C is a programming language developed at AT & T’s Bell Laboratories of USA in 1972.The C programming language is a standardized programming language developed. 2) What is an algorithm? An algorithm is a step-by-step method of performing any task. 3) What is a flow chart? A flowchart is a type of diagram that represents an algorithm or process, showing the steps as boxes of various kinds, and their order by connecting these with arrows. 4) What is a C Preprocessor? C Preprocessor is a program that processes our source program before it is passed to the compiler. 5) What is the use of header files as used in C programming? Header files are used to have declarations.It is simple to include a single header file than writing all the needed functions prototypes. 6) What is the Structure of a C Program? Documentation Section Linking Section Definition Section Global declaration Section main function subprogram section. 7) Explain some Header Files? stdio.h This is standard i/o header file in which Input/Output functions are declared conio.h This is console input/output header file string.h All string related functions are defined in this header file stdlib.h This header file contains general functions used in C programs math.h All maths related functions are defined in this header file
- 2. 8) What is the use of main() function? main() is the starting point of program execution. 9) What are the types of constants in c? C constants can be divided into two categories: 1. Primary constants (Numerical) 2. Secondary constants (Character) 10)What is a Compiler? A compiler is a computer program that transforms source code written in a programming language into another computer language 11)What is a Token in C? A Token is the basic building block of a C. C Tokens are:Key Words, Identifier, Constants, String – literal, Operator, Punctuators 12)What are Printf() and scanf() Functions : printf() function is used to print the “character, string, float, integer, octal and hexadecimal values” onto the output screen. scanf() function is used to read character, string, numeric data from keyboard 13)What is a Data Type and List the different Data types? C data types are defined as the data storage format that a variable can store a data to perform a specific operation. List of Data Types: 1. Basic Data Types: Int, Float, Char, Double, long int 2. Enumeration Data Type: enum 3. Derived Data Type: Pointer, array, structure, union 4. Void Data Type: void 14)What is Integer Data Type? Integer data type allows a variable to store numeric values. The storage size of int data type is 2 or 4 or 8 byte. int (2 byte) can store values from -32,768 to +32,767 int (4 byte) can store values from -2,147,483,648 to +2,147,483,647.
- 3. 15) What is enum Data Type? Enumeration data type consists of named integer constants as a list. It start with 0 (zero) by default and value is incremented by 1 for the sequential identifiers in the list. 16)What is a Void Data Type? Void is an empty data type that has no value. 17)What is a comment in C? Comments are like helping text in your C program and they are ignored by the compiler. We can write in between /* and */ or // (Line Comments) 18)What is an Identifier in C? C identifier is a name used to identify a variable,function,or any other user defined item. 19)What is a Key word in C? Keywords are reserved words in C and Keywords are may not be used as constant or variable or any other identifier names. some of the Keywords: Else,long,break,char,float. 20)Define a Variable? A variable is nothing but a name given to a storage area that our programs can manipulate.Each variable in C has a specific type, which determines the size and layout of the variable's memory. 21)What are the steps to develop a C Program? Specifying the problem statement Designing an algorithm Coding Debugging Testing and Validating Documentation and Maintenance. 22)What is the process of debugging or compilation for C Programs? To check the errors in a program is called debugging done by 4 stage: 1. Checking Syntactic Errors 2. Checking Run time Errors/ Linkage Errors 3. Checking Linker Errors 4. Checking Logical Errors
- 4. 23) What is an Operator and list different types of operators in C? The symbols which are used to perform logical and mathematical operations in a C program are called C operators. different operators in C: Arithmetic operators Relational operators Logical operators Assignment operators Increment and Decrement operators Conditional operators Bitwise operators Special operators. 24)What are Special Operators? &(Address Operator) *(Pointer Operator) Sizeof() 25)What is sizeof operator? It returns the number of bytes the operand occupies. 26) What is pre-increment or post-increment? ++n (pre increment) increments n before its value is used in an assignment operation or any expression containing it. n++ (post increment) does increment after the value of n is used. 27)What is type casting? Converting a variable of one type to another type. 28)What are the Format Specifiers or Type Specifiers or Conversion Specifiers? %d (Integer) %f (Float) %c (Character) %l (Long Integer) %s (Strings) %u (Address with decimal value) %p (Address with Hexa Decimal Value in Small Letters) %x ((Address with Hexa Decimal Value in Capital Letters)
- 5. 29)What is a Statement in C? A statement is a block of code that does something. 30)Different Types of Statements? Null Statement Expression Statement Compound Statement Return Statement Conditional Statements Iterative or Looping Statements Unconditional Statements 31)What are different types of conditional statements? If Statement If else statement Nested- if else statement Switch Statement 32)What is Looping Statements? Looping statement which executes the statements with in the compound statement by checking the condition, and performs same set of statements as a loop until the condition false. Looping Statements are: While, do-while, for 33)What is the difference between for loop and while loop? For Loop:execute a set of statements in fixed number of times. While loop:when the number of iterations to be performed is not known in advance. 34)What are Unconditional Statements? goto and labeled statements break Statement continue Statement. 35)Define goto and labeled Statement.,Break Statement,Continue Statement The goto statement transfers control to a label. The given label must reside in the same function and can appear before only one statement in the same function. The break statement terminates the execution of the nearest enclosing do, for, switch, or while statement in which it appears. Control passes to the statement that follows the terminated statement.
- 6. The continue statement passes control to the next iteration of the nearest enclosing do, for, or while statement in which it appears 36)Define Type Qualifiers, and list them? The keywords which are used to modify the properties of a variable are called typequalifiers.There are two types of qualifiers available in C language.They are,1) const 2)volatile 37) Define const Keyword? Constants are also like normal variables. They refer to fixed values. They are alsocalled as literals. 38)Define volatile Keyword? When a variable is defined as volatile, the program may not change the value of the variable explicitly. 39)Define Storage class? Storage class specifiers in C language tells the compiler where to store a variable, how to store the variable, what is the initial value of the variable and life time of the variable. 40)What are Different Storage Classes? There are 4 storage class specifiers available in C language. They are, 1. Auto 2. Extern 3. Static 4. Register 41)Define Array? An Array is a collection of Homogeneous or similar data type elements having unique values, and stored data different locations.You can store group of data of same data type in an array. Types of an Array: There are 2 types of C arrays. They are, 1) One dimensional array 2) Multi dimensional array a) Two dimensional array b) Three dimensional array, four dimensional array etc…
- 7. 42)Define a String? C Strings are nothing but array of characters ended with null character (‘0’).Strings are always enclosed by double quotes. Whereas, character is enclosed by single quotes in C. 43)Define Pointer? C Pointer is a variable that stores/points the address of another variable. C Pointer is used to allocate memory dynamically i.e. at run time. 44) What is a pointer value and address? pointer to pointer? A pointer value is a data object that refers to a memory location. Each memory location is numbered in the memory. The number attached to a memory location is called the address of the location. If a pointer variable points another pointer value. Such a situation is known as a pointer to a pointer. 45) What are the Advantages of Functions? It reduces the Complexity in a program by reducing the code. Function are easily understanding and reliability and execution is faster. 46)What is Recursion? A recursion function is one which calls itself either directly or indirectly it must halt at a definite point to avoid infinite recursion. 47) What is an Argument? An argument is an entity used to pass data from the calling to a called function. 48) Define Function Declaration, Function Call and Function Definition. Function declaration - This informs compiler about the function name, function parameters and return value’s data type. Function call – This calls the actual function Function definition – This contains all the statements to be executed. 49)Define Call by Value and Call by Reference? In call by value method, the value of the variable is passed to the function as Parameter. In call by reference method, the address of the variable is passed to the function as parameter.
- 8. 50) List some MATH.H Functions? 1. abs ( ) 2. floor ( ) 3. round.(.) 4. ceil ( ) 5. sqrt ( ) 6. pow ( ) 7. trunc()