22. How Many Types Of Logical Operators Are There In 'C' Programming Language?
Answer: C allows usage of three logical operators:
(4 == 4) && (5!= 1) evaluates to True (1), because both operands are true.
(4 > 1) || (9 < 1) evaluates to True (1), because one operand is true (4 > 1).
!(5 == 4) evaluates to True (1), because the operand is false.
23. What Is A Constant Variable?
Answer: By default the value of any variable in C is not constant. Hence, to assign a variable with a constant value throughout the program, the variable can be made a constant variable. Constant variable are declared using the const keyword and they make execution faster than non-constant variables.
24. Define Static Variable?
Answer: A static variable is a variable which has been allocated statically. i.e., the life of the variable extends as long as the entire run of the program. Static variables are global variables and find wide use in programs. It is declared as:
static datatype variable;
25. What Is A Register Variable?
Answer: Register variables are special variants of automatic variables. Register variables are stored in processor registers. The system register provides a certain control of efficiency of the program when variables are declared as register variables.
26. Where Is An Auto Variable Stored?
Answer: An auto variable is stored in the computer’s main memory.
27. What Is Meant By Scope & Storage Allocation Of A Variable Or Function?
Answer: The scope of a variable is defined by the storage allocation of that variable. Storage allocation of a variable decides the memory part where storage space is allocated for a particular variable or function.
28. What Is The Scope & Storage Allocation Of Extern & Global Variables?
Answer: Extern variables are global variables. These variables belong to the external storage class and are stored in the system’s main memory. They are declared in a separate source file which could be outside the current program scope. The scope of these variables is global.
Global variables are variables declared above the main function. They are accessible throughout the program. They have 0 as the default value.
29. What Is The Scope & Storage Allocation Of Register?
Answer: Register variables are storage allocated in the CPU registers. Since they are stored in the CPU registers, their storage and accessibility is much easier and faster than other variables. The scope of register variables is local to the blocks in which they are defined.
30. What Is The Scope & Storage Allocation Of Static & Local Variables?
Answer: The storage allocation of static variables is done at the beginning of program execution. After the program terminates, the memory is reallocated. Scope of static variables is local to the block within which they are defined.
Local variables are variables defined within a function or program. Their default value is a garbage value and they are accessed only by the particular function or program.
Check Out Other Questions:
21) What is the purpose of main() function?
22) What are the differences between formal arguments and actual arguments of a function?
23) What is call by value in functions?
24) What is call by reference in functions?
25) What are the differences between getchar() and scanf() functions for reading strings?
26) Out of the functions fgets() and gets(), which one is safer to use and why?
27) What is the difference between the functions strdup() and strcpy()?
28) What is recursive function?
29) What is the difference between defining and declaring a variable?
30) What is a constant variable?
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