general Interview Questions on C-Program

• What is a pointer on pointer?
• Distinguish between malloc() & calloc() memory allocation.
• What is keyword auto for?
• What are the valid places for the keyword break to appear.
• Explain the syntax for for loop.
• What is difference between including the header file with-in angular braces < > and double quotes “ “
• How a negative integer is stored.
• What is a static variable?
• What is a NULL pointer?
• What is the purpose of extern storage specifier?
• Explain the purpose of the function sprintf().
• What is the meaning of base address of the array?
• When should we use the register storage specifier?
• S++ or S = S+1, which can be recommended to increment the value by 1 and why?
• What is a dangling pointer?
• What is the purpose of the keyword typedef?
• What is lvalue and rvalue?
• What is the difference between actual and formal parameters?
• Can a program be compiled without main() function?
• What is the advantage of declaring void pointers?
• Where an automatic variable is stored?
• What is a nested structure?
• What is the difference between variable declaration and variable definition?
• What is a self-referential structure?
• Does a built-in header file contains built-in function definition?
• Explain modular programming.
• What is a token?
• What is a preprocessor?
• Explain the use of %i format specifier w.r.t scanf().
• How can you print a \ (backslash) using any of the printf() family of functions.
• Does a break is required by default case in switch statement?
• When to user -> (arrow) operator.
• What are bit fields?
• What are command line arguments?
• What are the different ways of passing parameters to the functions? Which to use when?
• What is the purpose of built-in stricmp() function.
• Describe the file opening mode “w+”.
• Where the address of operator (&) cannot be used?
• Is FILE a built-in data type?
• What is reminder for 5.0 % 2?
• How many operators are there under the category of ternary operators?
• Which key word is used to perform unconditional branching?
• What is a pointer to a function? Give the general syntax for the same.
• Explain the use of comma operator (,).
• What is a NULL statement?
• What is a static function?
• Which compiler switch to be used for compiling the programs using math library with gcc compiler?
• Which operator is used to continue the definition of macro in the next line?
• Which operator is used to receive the variable number of arguments for a function?
• What is the problem with the following coding snippet?
• Which built-in library function can be used to re-size the allocated dynamic memory?
• Define an array.
• What are enumerations?
• Which built-in function can be used to move the file pointer internally?
• What is a variable?
• Who designed C programming language?
• C is successor of which programming language?
• What is the full form of ANSI?
• Which operator can be used to determine the size of a data type or variable?
• Can we assign a float variable to a long integer variable?
• Is 068 a valid octal number?
• What it the return value of a relational operator if it returns any?
• How does bitwise operator XOR works.
• What is an infinite loop?
• Can variables belonging to different scope have same name? If so show an example.
• What is the default value of local and global variables?
• Can a pointer access the array?
• What are valid operations on pointers?
• What is a string length?
• What is the built-in function to append one string to another?
• Which operator can be used to access union elements if union variable is a pointer variable?
• Explain about ‘stdin’.
• Name a function which can be used to close the file stream.
• What is the purpose of #undef preprocessor?
• Define a structure.
• Name the predefined macro which be used to determine whether your compiler is ANSI standard or not?
• What is typecasting?
• What is recursion?
• Which function can be used to release the dynamic allocated memory?
• What is the first string in the argument vector w.r.t command line arguments?
• How can we determine whether a file is successfully opened or not using fopen() function?
• What is the output file generated by the linker.
• What is the maximum length of an identifier?
• What is the default function call method?
• Functions must and should be declared. Comment on this.
• When the macros gets expanded?
• Can a function return multiple values to the caller using return reserved word?
• What is a constant pointer?
• To make pointer generic for which date type it need to be declared?
• Can the structure variable be initialized as soon as it is declared?
• Is there a way to compare two structure variables?
• Which built-in library function can be used to match a patter from the string?
• What is difference between far and near pointers?
• Can we nest comments in a C code?
• Which control loop is recommended if you have to execute set of statements for fixed number of times?
• What is a constant?
• Can we use just the tag name of structures to declare the variables for the same?
• Can the main() function left empty?
• Can one function call another?
• Apart from Dennis Ritchie who the other person who contributed in design of C language.