C Interview Questions
Questions Answers Views Company eMail

what is the difference between getch() and getchar()?

Infosys, Huawei,

10 23355

what is the use of getch() function in C program.. difference b/w getch() and getche()??

IBM, Wipro, Infosys, TCS, HCL,

29 69309

how to implement stack work as a queue?

2 3913




write a c programs to do multiplication of two numbers with out using arithmatic operator ??????????

Infosys, TCS,

7 16149

what is the differnce between AF_INET and PF_INET?

Wipro, Systems Plus,

5 23926

1.what are local and global variables? 2.what is the scope of static variables? 3.what is the difference between static and global variables? 4.what are volatile variables? 5.what is the use of 'auto' keyword? 6.how do we make a global variable accessible across files? Explain the extern keyword? 7.what is a function prototype? 8.what does keyword 'extern' mean in a function declaration?

772

9.how do you write a function that takes a variable number of arguments? What is the prototype of printf () function? 10.How do you access command-line arguments? 11.what does ‘#include’ mean? 12.what is the difference between #include<> and #include”…”? 13.what are # pragma staments? 14.what is the most appropriate way to write a multi-statement macro?

1 1843

15.what is the disadvantage of using macros? 16.what is the self-referential structure? 17.can a union be self-referenced? 18.What is a pointer? 19.What is the Lvalue and Rvalue? 20.what is the difference between these initializations? 21.Char a[]=”string”; 22.Char *p=”literal”; 23.Does *p++ increment p, or what it points to?

1 2774




24.what is a void pointer? 25.why arithmetic operation can’t be performed on a void pointer? 26.differentiate between const char *a; char *const a; and char const *a; 27.compare array with pointer? 28.what is a NULL pointer? 29.what does ‘segmentation violation’ mean? 30.what does ‘Bus Error’ mean? 31.Define function pointers? 32.How do you initialize function pointers? Give an example? 33.where can function pointers be used?

709

34.what are bitwise shift operators? 35.what are bit fields? What is the use of bit fields in a structure declaration? 36.what is the size of an integer variable? 37.what are the files which are automatically opened when a c file is executed? 38.what is the little endian and big endian? 39.what is the use of fflush() function? 40.what is the difference between exit() and _exit() functions? 41.where does malloc() function get the memory? 42.what is the difference between malloc() and calloc() function? 43.what is the difference between postfix and prefix unary increment operators?

728

44.what is the difference between strcpy() and memcpy() function? 45.what is output of the following statetment? 46.Printf(“%x”, -1<<4); ? 47.will the program compile? int i; scanf(“%d”,i); printf(“%d”,i); 48.write a string copy function routine? 49.swap two integer variables without using a third temporary variable? 50.how do you redirect stdout value from a program to a file? 51.write a program that finds the factorial of a number using recursion?

3 3872

52.write a “Hello World” program in “c” without using a semicolon? 53.Give a method to count the number of ones in a 32 bit number? 54.write a program that print itself even if the source file is deleted? 55.Given an unsigned integer, find if the number is power of 2?

9 5892

1.what are local and global variables? 2.what is the scope of static variables? 3.what is the difference between static and global variables? 4.what are volatile variables? 5.what is the use of 'auto' keyword? 6.how do we make a global variable accessible across files? Explain the extern keyword? 7.what is a function prototype? 8.what does keyword 'extern' mean in a function declaration?

nvidia,

2 4581

9.how do you write a function that takes a variable number of arguments? What is the prototype of printf () function? 10.How do you access command-line arguments? 11.what does ‘#include’ mean? 12.what is the difference between #include<> and #include”…”? 13.what are # pragma staments? 14.what is the most appropriate way to write a multi-statement macro?

L&T,

4 5644

15.what is the disadvantage of using macros? 16.what is the self-referential structure? 17.can a union be self-referenced? 18.What is a pointer? 19.What is the Lvalue and Rvalue? 20.what is the difference between these initializations? 21.Char a[]=”string”; 22.Char *p=”literal”; 23.Does *p++ increment p, or what it points to?

CTS,

2 8580


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Un-Answered Questions { C }

Write the test cases for checking a variable having value in range -10.0 to +10.0?

924


how to execute a program using if else condition and the output should enter number and the number is odd only...

861


In cryptography, you could often break the algorithm if you know what was the original (plain) text that was encoded into the current ciphertext. This is called the plain text attack. In this simple problem, we illustrate the plain text attack on a simple substitution cipher encryption, where you know each letter has been substituted with a different letter from the alphabet but you don’t know what that letter is. You are given the cipherText as the input string to the function getwordSets(). You know that a plain text "AMMUNITION" occurs somewhere in this cipher text. Now, you have to find out which sets of characters corresponds to the encrypted form of the "AMMUNITION". You can assume that the encryption follows simple substitution only. [Hint: You could use the pattern in the "AMMUNITION" like MM occurring twice together to identify this]

1168


1. Write a function to display the sum of two numbers in the following ways: By using (i) pass by value (ii) pass by address a. function with argument and with return value b. function with argument and without return value c. without argument , with return value d. without argument , without return value Note: Use pass by address.

1548


write a c program for swapping two strings using pointer

1307






How to write a program for machine which is connected with server for that server automatically wants to catch the time for user of that machine?

868


Which is the memory area not included in C program? give the reason

777


Write a C program linear.c that creates a sequence of processes with a given length. By sequence it is meant that each created process has exactly one child. Let's look at some example outputs for the program. Here the entire process sequence consists of process 18181: Sara@dell:~/OSSS$ ./linear 1 Creating process sequence of length 1. 18181 begins the sequence. An example for a sequence of length three: Sara@dell:~/OSSS$ ./linear 3 Creating process sequence of length 3. 18233 begins the sequence. 18234 is child of 18233 18235 is child of 18234 ........ this is coad .... BUt i could not compleate it .....:( #include #include #include #include int main(int argc, char *argv[]) { int N; pid_t pid; int cont; if (argc != 2) { printf("Wrong number of command-line parameters!\n"); return 1; } N = atoi(argv[1]); printf("Creating process sequence of length %d.\n",N); printf("%d begins the sequence.\n",getpid()); /* What I have to do next ?????? */ }

861


can any one tel me wt is the question pattern for NIC exam

838


pierrot's divisor program using c or c++ code

984


Why is it important to memset a variable, immediately after allocating memory to it ?

813


Agonistic behavior, or aggression, is exhibited by most of the more than three million species of animals on this planet. Animal behaviorists still disagree on a comprehensive definition of the term, hut aggressive behavior can be loosely described as any action that harms an adversary or compels it to retreat. Aggression may serve many purposes, such as Food gathering, establishing territory, and enforcing social hierarchy. In a general Darwinian sense, however, the purpose of aggressive behavior is to increase the individual animal’s—and thus, the species’—chance of survival. Aggressive behavior may he directed at animals of other species, or it may be conspecific—that is, directed at members of an animal’s own species. One of the most common examples of conspecific aggression occurs in the establishment and maintenance of social hierarchies. In a hierarchy, social dominance is usually established according to physical superiority; the classic example is that of a pecking order among domestic fowl. The dominance hierarchy may be viewed as a means of social control that reduces the incidence of attack within a group. Once established, the hierarchy is rarely threatened by disputes because the inferior animal immediately submits when confronted by a superior. Two basic types of aggressive behavior are common to most species: attack and defensive threat. Each type involves a particular pattern of physiological and behavioral responses, which tends not to vary regardless of the stimulus that provokes it. For example, the pattern of attack behavior in cats involves a series of movements, such as stalking, biting, seizing with the forepaws and scratching with tile hind legs, that changes very little regardless of the stimulus—that is, regardless of who or what the cat is attacking. The cat’s defensive threat response offers another set of closely linked physiological and behavioral patterns. The cardiovascular system begins to pump blood at a faster rate, in preparation for sudden physical activity. The eves narrow and the ears flatten against the side of the cat’s head for protection, and other vulnerable areas of the body such as the stomach and throat are similarly contracted. Growling or hissing noises and erect fur also signal defensive threat. As with the attack response, this pattern of responses is generated with little variation regardless of the nature of the stimulus. Are these aggressive patterns of attack and defensive threat innate, genetically programmed, or are they learned? The answer seems to be a combination of both. A mouse is helpless at birth, but by its l2th day of life can assume a defensive threat position by backing up on its hind legs. By the time it is one month old, the mouse begins to exhibit the attack response. Nonetheless, copious evidence suggests that animals learn and practice aggressive behavior; one need look no further than the sight of a kitten playing with a ball of string. All the elements of attack—stalking, pouncing, biting, and shaking—are part of the game that prepares the kitten for more serious situations later in life. 7) The passage asserts that animal social hierarchies are generally stable because: a) the behavior responses of the group are known by all its members. b) the defensive threat posture quickly stops most conflicts. c) inferior animals usually defer to their physical superior. d) the need for mutual protection from other species inhibits conspecific aggression. 8) According to the author, what is the most significant physiological change undergone by a cat assuming the defensive threat position? a) An increase in cardiovascular activity b) A sudden narrowing of the eyes c) A contraction of the abdominal muscles d) The author does not say which change is most significant 9) Based on the information in the passage about agonistic behavior, it is reasonable to conclude that: I. the purpose of agonistic behavior is to help ensure the survival of the species. II. agonistic behavior is both innate and learned. III. conspecific aggression is more frequent than i aggression. a) I only b) II only c) I and II only d) I,II and III only 10) Which of the following would be most in accord with the information presented in the passage? a) The aggressive behavior of sharks is closely inked to their need to remain in constant motion. b) fine inability of newborn mice to exhibit the attack response proves that aggressive behavior must be learned. c) Most animal species that do riot exhibit aggressive behavior are prevented from doing so by environmental factors. d) Members of a certain species of hawk use the same method to prey on both squirrels and gophers. 11) The author suggests that the question of whether agonistic behavior is genetically programmed or learned: a) still generates considerable controversy among animal behaviorists. b) was first investigated through experiments on mice. c) is outdated since most scientists now believe the genetic element to be most important. d) has been the subject of extensive clinical study. 12) Which of the following topics related to agonistic behavior is NOT explicitly addressed in the passage? a) The physiological changes that accompany attack behavior in cats b) The evolutionary purpose of aggression c) Conspecific aggression that occurs in dominance hierarchies d) The relationship between play and aggression 13) The author of this passage is primarily concerned with: a) analyzing the differences between attack behavior and defensive threat behavior. b) introducing a subject currently debated among animal behaviorists. c) providing a general overview of aggressive behavior in animals. d) illustrating various manifestations of agonistic behavior among mammals.

1046


2) Write a program that will help Air Traffic Control for an airport to view the sequence of flights ready for take-off. The airport can accommodate 10 flights waiting for take-off at any point in time. Each flight has a unique 3 digit numeric identifier.  Each time a flight takes-off, Air Traffic Control adds a flight to the waitlist. Each time a flight is added to the waitlist, the list of flights waiting to take-off must be displayed.  When a flight is cleared for take-off, Air Traffic Control removes the flight from the waitlist. Each time a flight takes-off, the list of flights waiting to take-off must be displayed.  Sequence of take-off is the sequence of addition to the waitlist

1790


application attempts to perform an operation?

711


we need to calculating INCOME TAX for the person. The INCOME TAX is as follows:- First $10000/- of income : 4% tax Next $10000/- of income : 8% tax Next $10000/- of income : 11.5% tax above $10, 00,00/- : 15% tax What is the Solution of this Question ?

54