What is Variable? What is the need for variables? What are the rules for naming variables. Give examples.

3 years ago

C Programming

Definition of Variable

Variable is an identifier used to name the memory location which holds the value. Variable is an entity whose value can be changed (Not Fixed) during the program execution. Need for variables

It may help to think of variables as a placeholder for a value or data. You can think of a variable as being equivalent to its assigned value or data. In a C program, if a user wants to store and use any data then the user must create variables in a program to store the required data.

Rules for naming a Variable

The variables must always begin with a letter or underscore as the first
The following letters can be any number of letters, digits or underscore.
Maximum length of any identifier is 31 characters for external names or 63 characters for local
Identifiers are case Ex. Rate and RaTe are two different identifiers.
The variable name should not be a
No special symbols are allowed except underscore. Examples:

Valid identifiers:

Sum roll_no _name sum_of_digits avg_of_3_nums

Invalid Identifiers and reason for invalid:

$roll_no - Name doesn‟t begin with either letter or underscore

for - keyword is used as name

sum,1 - special symbol comma is not allowed

3_factorial - name begins with digit as first letter

0

Sanisha Maharjan

Sanisha Maharjan

Jan 20, 2022

More related questions

1. What Is Nested Structure?

2. Explain Difference Between Binary File And Text Files.

3. What Is Array? Explain 1D Array.

4. Why Need Of Masking Bit Field.

5. What Is Bitwise Operator? Explain Left Shift And Right Shift.

6. Diference Between Call By Value And Call By Reference

7. Write The Program To Concatenate Two String Without Using String Library Function?

8. What Is The Pointer? Explain.

9. What Is Making Bit Field.

10. Difference Between String And Character Array.

11. What Is The File? Explain The Modes Of Files.

12. Define Macro. How To Substitute The Macro Directives In Our Program?

13. What Is Structure And Union? How To Deferent Union By Structure. What Is Deference Between Them?

14. What Is String? Explain All Library Function Of String.

15. Define Pointer? Explain All Function Of DMA (Dynamic Memory Allocation).

16. What Is An Array? Explain 2D Array With Memory Representation.

17. C Program to Find the Largest Number Among Three Numbers

18. Write a program in c to find prime number or not

19. Write a program in c to find the division of student

20. C program to read data from file using fgets() function

21. C Program to read data from file using fgetc() function

22. Write C program to accept the details of employee and display them using structure. Details consist of Employee ID, Name, Designation, Department, Salary

23. Write C program to read the details of two workers and calculate total payment of workers using structure

24. Programming Language 2015 - BCIS (PU) Old Question

25. Which escape character can be used to beep from speaker in c

26. Evaluate the following expression in C Programming

27. Write the C expression for the following: i) A = 5𝑥+3𝑦/𝑎+𝑏 ii) C = e^|𝑥+𝑦−10| iii) D = e√𝑥+e√𝑦 / 𝑥𝑠i𝑛√𝑦 iv) B = √𝑠(𝑠 − 𝑎)(𝑠 − 𝑏)(𝑠 − 𝑐) v) E = 𝑥^25 + 𝑦^35 Vi) X = −b + √𝑏2−4𝑎𝑐 / 2𝑎

28. Write an algorithm to find sum and average of N numbers.

29. Write a C program that computes the size of int, float, double and char variables.

30. WACP to convert temperature in Fahrenheit into temperature in Celsius.

31. WACP to convert temperature in Celsius into temperature in Fahrenheit.

32. WACP to find sum and average of three given numbers.

33. WACP to find area and perimeter of a rectangle.

34. WACP to find diameter, area and perimeter of a circle.

35. What is the value of X in the following code segments? Justify your answers. i) int a,b; float x; a=4; b=5; ii) int a,b; float x; a=4; b=5; x = (float) b/a;x=b/a;

36. WACP to which takes p,t,r as input and compute the simple interest and display the result.

37. What is precedence and associativity rule? Explain with precedence table.

38. What is type conversion? Explain different types of conversion.

39. What are operators and expressions? Explain different types of operators and expressions with examples.

40. What are input and output functions? Explain printf() and scanf() functions with examples.

41. What is Variable? How to Declare and initialize variables? Give examples.

42. Give general structure of C program. Explain with an example program.

43. What is datatype? List and explain different datatypes with examples.

44. What are identifiers? What are the rules for naming a identifier? Give examples.

45. What are Keywords? List all keywords and thier purpose/importance.

46. What are C-Tokens? List and define different C-Tokens with examples.

47. What are the alphabets or character set of C programming language?

48. What is flowchart? List and define the purpose of symbols used to represent flowchart. Give an example for flowchart.

49. What is pseudocode? Give an example for pseudocode.

50. What is algorithm? Write the characteristics of an algorithm. Give an example for algorithm.

51. Dothese two program statements perform the same output? 1) scanf("%c", &letter); 2) letter=getchar()

52. What is the difference between functions getch() and getche()?

53. Which function in C can be used to append a string to another string?

54. What does the function toupper() do?

55. When is a "switch" statement preferable over an "if" statement?

56. Write a simple code fragment that will check if a number is positive or negative.

57. What is the difference between functions abs() and fabs()?

58. What is a newline escape sequence?

59. What is the advantage of a random access file?

60. What is the use of a semicolon (;) at the end of every program statement?

61. Create a simple code fragment that will swap the values of two variables num1 and num2.

62. How do you convert strings to numbers in C?

63. What are the advantages and disadvantages of a heap?

64. Is there a built-in function in C that can be used for sorting data?

65. How do you search data in a data file using random access method?

66. The % symbol has a special use in a printf statement. How would you place this character as part of the output on the screen?

67. What is gets() function?

68. Can you pass an entire structure to functions?

69. What are pointers?

70. Describe how arrays can be passed to a user defined function

71. In a switch statement, what will happen if a break statement is omitted?

72. What is the general form of a C program?

73. What are the different data types in C?

74. What is dynamic data structure?

75. is it possible to create your own header files?

76. What is the difference between text files and binary files?

77. What does the characters "r" and "w" mean when writing programs that will make use of files?

78. What are structure types in C?

79. What are multidimensional arrays?

80. Is it possible to have a function as a parameter in another function?

81. What are enumerated types?

82. What are global variables and how do you declare them?

83. What are control structures?

84. What are formal parameters?

85. What are run-time errors?

86. What is output redirection?

87. What are actual arguments?

88. Is this program statement valid? INT = 10.50;

89. What is wrong with this program statement? void = 10;

90. What is a program flowchart and how does it help in writing a program?

91. What is an endless loop?

92. In C language, the variables NAME, name, and Name are all the same. TRUE or FALSE?

93. What is the difference between the expression "++a" and "a++"?

94. Not all reserved words are written in lowercase. TRUE or FALSE?

95. What are binary trees?

96. What is FIFO?

97. What are linked list?

98. What are reserved words?

99. What are the different file extensions involved when programming in C?

100. Why is C language being considered a middle level language?

101. Is it possible to initialize a variable at the time it was declared?

102. Is it possible to initialize a variable at the time it was declared?

103. How do you determine the length of a string value that was stored in a variable?

104. What is wrong with this statement? myName = "Robin";

105. Describe the order of precedence with regards to operators in C.

106. What will be the outcome of the following conditional statement if the value of variable s is 10?

107. What are preprocessor directives?

108. Can the "if" function be used in comparing strings?

109. What is || operator and how does it function in a program?

110. What are the different types of control structures in programming?

111. What are logical errors and how does it differ from syntax errors?

112. What does the format %10.2 mean when included in a printf statement?

113. In C programming, what command or code can be used to determine if a number of odd or even?

114. What does the && operator do in a program code?

115. What is debugging?

116. What are comments and how do you insert it in a C program?

117. What could possibly be the problem if a valid function name such as tolower() is being reported by the C compiler as undefined?

118. How do you generate random numbers in C?

119. What is wrong in this statement? scanf("%d",whatnumber);

120. Write a loop statement that will show the following output:

121. What is the advantage of an array over individual variables?

122. What is the significance of an algorithm to C programming?

123. What are compound statements?

124. When is the "void" keyword used in a function?

125. Why is it that not all header files are declared in every C program?

126. Can two or more operators such as \n and \t be combined in a single line of program code?

127. Can I use "int" data type to store the value 32768? Why?

128. How do you access the values within an array?

129. What are variables and it what way is it different from constants?

130. What is syntax error?

131. What are header files and what are its uses in C programming?

132. Can the curly brackets { } be used to enclose a single line of code?

133. How do you declare a variable that will hold string values?

134. Compare and contrast compilers from interpreters.

135. Which of the following operators is incorrect and why? ( >=, <=, <>, ==)

136. What is a nested loop?

137. What is the modulus operator?

138. What is the difference between the = symbol and == symbol?

139. What is the use of a '\0' character?

140. In C programming, how do you insert quote characters (' and ") into the output screen?

141. Differentiate Source Codes from Object Codes

142. What is spaghetti programming?

143. What is variable initialization and why is it important?

144. What is a sequential access file?

145. What is a stack?

146. What is the equivalent code of the following statement in WHILE LOOP format?

147. Some coders debug their programs by placing comment symbols on some codes instead of deleting it. How does this aid in debugging?

148. What is the difference between Call by Value and Call by Reference?

149. How do you construct an increment statement or decrement statement in C?

150. Implement Priority Queue using Heap C Programming.

151. Implement a simple Heap C Programming.

152. Implement Binary Search Tree using List C Programming.

153. Implement Queue using List C Programming.

154. Write a C Program to perform following operations on Circular Linked List ADT

155. Write a C Program to perform following operations on Doubly Linked List ADT

156. Linked list C Programming

157. Queue ADT Implement Queue using Arrays C Programming.

158. Stack ADT Implement Stack using Arrays in C Programming.

159. Demonstrate the technique of recursion in C Recursion – Write recursive function for

160. Write a C program to demonstrate Enumerations, Structures and Union data types.

161. Write a C program to demonstrate the operations on strings – by writing user defined string functions

162. Write a C program to demonstrate the input and output operations on strings

163. Write a C program to demonstrate the memory leaks when pointers are not used properly.

164. Write a C program to demonstrate the use of allocating a memory and freeing.

165. Writing a Swap Function: Write a C program to swap two numbers using pointers concept

166. Write C program to demonstrate the use of pointers by printing memory address

Questions Bank

View all Questions