C Language: Question Bank

framework from interrogate Mantra. take on to liberate updates via email. Material from hearing Mantra. Subscribe to sluttish updates via email. Favourite 50 C reference Question lingo for freshers and experienced IT coursemers Writdecade by Madhulika Reddy and Dhoka Ratan. Edited and Published by Sridhar Jammalamadaka Get the in vogue(p) updates and news on topics C atomic subjugate 18r and Education from c alone into question Mantra Subscribe to interrogate Mantra for sinless. ABOUT THIS BOOK This deem comprises of Interview Questions and Answers collected from the famous cargoner advice blog www. InterviewMantra. et The aim of this track record is to help freshers and experienced schedulemers to rapidly brush up the basic concepts of C language. This debateersign quite a little be ingestiond as a quick study guide before attend a job call into question which requires k directlyledge of C syllabusming language. The questions that appear in this rule boo k argon few of the virtually frequently asked questions in IT patronage interviews in top MNC companies. All the questions have been neatly answered and have been supported with example code wheresoever applicable. A push-down stock of effort has been put into this book to make the answers as accurate as possible, scarce no warranty or fitness is implied.The authors and the publishing firm shall have neither liability nor responsibility to whatsoever person or entity with respect to any privation or damages arising from the information contained in this book or from the practise of the plans accompanying it. Please lodge your feedback to us via email to emailprotected net COPYRIGHT info C language Interview Question Bank by Sridhar Jammalamadaka is licensed under a fictive Commons Attribution-Sh atomic modus operandi 18 Alike 2. 5 India License. Based on a work at www. interviewmantra. net. In elementary words, you whitethorn use this work for commercial purposes, re mix the work, produce it by any means, provided ou keep a colligate to http//www. interviewmantra. net and attribute the work to the owner Sridhar Jammalamadaka. confine AT A GLANCE 1. 2. 3. 4. 5. Chapter Name pg-no Variables & encounter cling . . . . . . . . . . . . . . . . . . . . 6 Operators, incessants & Structures . . . . . . . . . . . .11 Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 Pointers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Material from Interview Mantra. Subscribe to free updates via email. TABLE OF CONTENTSCHAPTER 1 Variables & Control Flow 1. What is the difference in the midst of declaring a changeable and defining a versatile? 2. What is a motionless inconsistent? 3. What is a register inconstant? 4. Where is an auto unsettled stored? 5. What is range of a function & terminal entrepot apportionment of extern and global inconstants? 6. What is scope & store parcelling of register, motionless and local unsettleds? 7. What are storage retrospect, fail apprise, scope and life of self-loading and exhibit storage consort? 8. What are storage warehousing, default honor, scope and life of Static and immaterial storage degree? 9. What is the difference betwixt swing and continue statements? 0. What is the difference amongst for and while closed circuits? CHAPTER 2 Operators, Constants & Structures 1. Which whilewise operator is fitted for reassureing whether a particular small-arm is ON or OFF? 2. Which bitwise operator is suitable for turning OFF a particular bit in a fleck? 3. What is equivalent of multiplying an unsigned int by 2 left channelize of go by 1 or right shift of keep down by 1? 4. What is an Enumeration Constant? 5. What is a grammatical construction? 6. What are the differences between a structure and a union? 7. What are the advantages of unions? 8. How cease display elusiondef be to define a type of structure? 9. import a course that returns 3 metrical composition from a purpose use a structure. 10. In code snippet below struct date int yr int day int month date1,date2 date1. yr = 2004 date1. day = 4 date1. month = 12 put out a wangle that assigns think ofs to date2. Arguments to the component must be pointers to the structure, Date and integer variables date, month, year. Material from Interview Mantra. Subscribe to free updates via email. CHAPTER 3 Functions 1. What is the purpose of principal(prenominal)() function? 2. Explain leave out line arguments of principal(prenominal) function? 3. What are brain loads? Are functions stated or defined in header deposits ? 4.What are the differences between formal arguments and real arguments of a function? 5. What is pass by measure in functions? 6. What is pass by reference in functions? 7. What are the differences between thread scorch() and scanf() functio ns for reading draw? 8. push through of the functions fgets() and gets(), which one is safer to use and why? 9. What is the difference between the functions strdup() and strcpy()? CHAPTER 4 Pointers 1. What is a pointer in C? 2. What are the advantages of using pointers? 3. What are the differences between malloc() and calloc()? 4. How to use realloc() to dynamically increase size of it of an already allocated start? . What is the equivalent pointer expression for referring an element aijkl, in a four dimensional roam? 6. have an array of three function pointers where each function receives two integers and returns float. 7. Explain the variable assignment in the declaration int *(*p10)(char *, char *) 8. What is the prise of sizeof(a) /sizeof(char *) in a code snippet char *a4=sridhar,raghava,shashi,srikanth 9. (i) What are the differences between the C statements below char *str = Hello char arr = Hello (ii) Whether following statements get complied or not?Explain each st atement. arr++ *(arr + 1) = s printf(%s,arr) CHAPTER 5 Programs 1. spare a weapons platform to find factorial of the granted fall. 2. put out a program to check whether the accustomed number is even or odd. 3. pull through a program to swap two add up using a temporary variable. 4. Write a program to swap two poetry without using a temporary variable. Material from Interview Mantra. Subscribe to free updates via email. 5. Write a program to swap two numbers using bitwise operators. 6. Write a program to find the great of three numbers. 7. Write a program to find the superior among ten numbers. . Write a program to check whether the given number is a prime. 9. Write a program to check whether the given number is a palindromic number. 10. Write a program to check whether the given string is a palindrome. 11. Write a program to generate the Fibonacci series. 12. Write a program to print Hello humans without using semicolon anywhere in the code. 13. Write a program to print a semicolon without using a semicolon anywhere in the code. 14. Write a program to compare two strings without using strcmp() function. 15. Write a program to concatenate two strings without using strcat() function. 16.Write a program to efface a specified line from a schoolbook file. 17. Write a program to replace a specified line in a text file. 18. Write a program to find the number of lines in a text file. 19. Write a C program which asks the user for a number between 1 to 9 and turn ins the number. If the user inputs a number out of the specified range, the program should show an error and prompt the user for a legitimate input. 20. Write a program to display the propagation table of a given number. Testimonials Anushka M says convey you soooo much for all these questions, along with the solutions. Its a great compilation.Thanks a lot guys. unidentified says Awesome. Thanks a ton for uploading this pdf, your concept was watch glass clear. Now I am very convinced(p) ab out myself. Now Im ready to face the interview challenge. Thanks once again. Urmi says Thank You.. Its Nice.. It saved my priceless Time.. Thanks a lot Rajakumari says Thank you so much Mr. Sridhar. No words to say , lot of thanks Very useful to freshers & experienced. Material from Interview Mantra. Subscribe to free updates via email. CHAPTER 1 Variables & Control Flow 1. What is the difference between declaring a variable and defining a variable?Declaration of a variable in C hints the compiler about the type and size of the variable in compile time. Similarly, declaration of a function hints about type and size of function parameters. No space is reserved in memory for any variable in case of declaration. ensample int a Here variable a is stated of data type int Defining a variable means declaring it and also allocating space to hold it. We can say Definition = Declaration + Space arriere pensee. slip int a = 10 Here variable a is described as an int to the compiler and memory is allocated to hold value 10. 2. What is a static variable?A static variable is a additional variable that is stored in the data segment unconnected the default automatic variable that is stored in stack. A static variable can be initialized by using keyword static before variable name. Example static int a = 5 A static variable behaves in a varied bearing depending upon whether it is a global variable or a local variable. A static global variable is same as an ordinary global variable except that it cannot be accessed by other files in the same program / project even with the use of keyword extern. A static local variable is different from local variable.It is initialized tho once no motion how many times that function in which it resides is called. It may be used as a count variable. Example ack directlyledge //program in file f1. c void count(void) static int count1 = 0 int count2 = 0 count1++ count2++ printf( take account of count1 is %d, shelter of count2 is % d, count1, count2) /*briny function*/ int main() count() count() count() return 0 Output Value of count1 is 1, Value of count2 is 1 Value of count1 is 2, Value of count2 is 1 Material from Interview Mantra. Subscribe to free updates via email. Value of count1 is 3, Value of count2 is 1 3. What is a register variable?Register variables are stored in the CPU registers. Its default value is a garbage value. background k outrightledge of a register variable is local to the intercept in which it is defined. spirit is till control remains in spite of appearance the occlusion in which the register variable is defined. Variable stored in a CPU register can forever be accessed quick than the one that is stored in memory. Therefore, if a variable is used at many places in a program, it is better to declare its storage ground level as register Example register int x=5 Variables for loop counters can be declared as register. Note that register keyword may be ignored by some compilers. . Where is an auto variables stored? Main memory and CPU registers are the two memory locations where auto variables are stored. Auto variables are defined under automatic storage figure. They are stored in main memory. Memory is allocated to an automatic variable when the full stop which contains it is called and it is de-allocated at the goal of its hinder execution. Auto variables terminal main memory. Default value garbage value. Scope local to the block in which the variable is defined. sprightliness till the control remains inside the block in which the variable is defined. 5.What is scope & storage allocation of extern and global variables? Extern variables live on to the out-of-door storage class and are stored in the main memory. extern is used when we have to refer a function or variable that is implemented in other file in the same project. The scope of the extern variables is globose. Example /*************** Index f1. c ****************/ acknowledge extern int x int main() printf(value of x %d, x) return 0 Index f2. c ****************/ int x = 3 Here, the program written in file f1. c has the main function and reference to variable x. The file f2. c has the declaration of variable x.The compiler should know the datatype of x and this is done by extern definition. Material from Interview Mantra. Subscribe to free updates via email. Global variables are variables which are declared above the main( ) function. These variables are accessible throughout the program. They can be accessed by all the functions in the program. Their default value is zero point. Example include int x = 0 /* Variable x is a global variable. It can be accessed throughout the program */ void increment(void) x = x + 1 printf( value of x %d, x) int main() printf( value of x %d, x) increment() return 0 6.What is scope & storage allocation of register, static and local variables? Register variables belong to the register storage class and are stored in the CPU registers. The scope of the register variables is local to the block in which the variables are defined. The variables which are used for more than number of times in a program are declared as register variables for faster access. Example loop counter variables. register int y=6 Static variables Memory is allocated at the branch of the program execution and it is reallocated only afterwards the program terminates.The scope of the static variables is local to the block in which the variables are defined. Example include void decrement() static int a=5 a printf(Value of a%d, a) int main() decrement() return 0 Here a is initialized only once. Every time this function is called, a does not get initialized. so output would be 4 3 2 etc. , Local variables are variables which are declared within any function or a block. They can be accessed only by function or block in which they are declared. Their default value is a garbage value. 7. What are storage memory, default value, scope and life of Automatic and Register storage class? . Automatic storage class Storage Default value main memory. garbage value. Material from Interview Mantra. Subscribe to free updates via email. Scope spirit Storage Default value Scope life history local to the block in which the variable is defined. till control remains within the block. CPU registers. garbage value. local to the block in which the variable is defined. till control remains within the block. 2. Register storage class 8. What are storage memory, default value, scope and life of Static and External storage class? 1. Static storage class Storage Default value ScopeLifetime Storage Default value Scope Lifetime main memory. zero local to the block in which the variable is defined. till the value of the variable persists between different function calls. main memory zero global as long as the program execution doesnt come to an end. 2. External storage class 9. What is the difference between feed and conti nue statements? Differences between break out and continue statements break 1. break is a keyword used to terminate the loop or exit from the block. The control jumps to next statement after the loop or block. 2. Syntax Statement 1 Statement 2 Statement n break 3. reak can be used with for, while, do- while, and switch statements. When break is used in nested loops i. e. within the inner most loop and then only the innermost loop is terminated. 4. Example i = 1, j = 0 while(i a && b c) printf(b is Greater than a and c) else if (c a && c b) printf(c is Greater than a and b) else printf(all are oppose or any two values are equal) return 0 Output Enter a,b,c 3 5 8 c is Greater than a and b Explanation with examples Consider three numbers a=5,b=4,c=8 if(ab && ac) then a is greater than b and c now check this actor for the three numbers 5,4,8 i. . if(54 && 58) /* 54 is true but 58 fails */ so the control shifts to else if condition else if(ba && bc) then b is greater than a and c now checking this condition for 5,4,8 i. e. else if(45 && 48) /* both the conditions fail */ now the control shifts to the next else if condition else if(ca && cb) then c is greater than a and b Material from Interview Mantra. Subscribe to free updates via email. now checking this condition for 5,4,8 i. e. else if(85 && 84) /* both conditions are satisfied */ Thus c is greater than a and b. 7.Write a program to find the sterling(prenominal) among ten numbers. Program include int main() int a10 int i int greatest printf(Enter ten values) //Store 10 numbers in an array for (i = 0 i 10 i++) scanf(%d, i) //Assume that a0 is greatest greatest = a0 for (i = 0 i 10 i++) if (ai greatest) greatest = ai printf(Greatest of ten numbers is %d, greatest) return 0 Output Enter ten values 2 53 65 3 88 8 14 5 77 64 Greatest of ten numbers is 88 Explanation with example Entered values are 2, 53, 65, 3, 88, 8, 14, 5, 77, 64 They are stored in an array of size 10. et a be an array holding these values. /* how the greatest among ten numbers is found */ Let us consider a variable greatest. At the beginning of the loop, variable greatest is assinged with the value of first element in the array greatest=a0. Here variable greatest is assigned 2 as a0=2. Below loop is executed until end of the array a. for(i=0 igreatest) greatest= ai For each value of i, value of ai is compared with value of variable greatest. If any value greater than the value of greatest is encountered, it would be replaced by ai.After completion of for loop, the value of variable greatest holds the greatest number in the array. In this case 88 is the greatest of all the numbers. Material from Interview Mantra. Subscribe to free updates via email. 8. Write a program to check whether the given number is a prime. A prime number is a natural number that has only one and itself as factors. Examples 2, 3, 13 are prime numbers. Program include main() int n, i, c = 0 printf(Enter any number n ) sca nf(%d, ) /*logic*/ for (i = 1 i