Explain the keyword continue.
• It is used to take the control to the beginning of the loop.
• It bypasses the statements inside the loop, which have not been executed.
• Continue statement is generally present within a loop and associated with if statement. Example:
int i, j;
for ( i=1 ; 1<=2 ; i++)
for ( j=1 ; j<=2; j++)
printf (“\n%d %d\n”,i,j);
Output of program is 12
When the continue statement takes control it bypasses the remaining statements of the inner for loop.
How are decisions made using a switch keyword?
• Switch is combined with case and default keywords to make a control statement.
• Syntax: switch(integer expression)
case constant 1:
case constant 2:
case constant n:
• The integer expression yields an integer value.
• This integer value is matched with case constant and if condition for any case is true it executes the statements following the case statement.
• If no case matches then statements following default are executed.
What is the K & R method to declare formal arguments in a function .
• K & R is called as the Kernighan and Ritchie method of declaring arguments.
calsum(x, y, z)
int x, y, z;
here x,y,z are the formal parameters.
• Here the values x, y, z are defined in the first statement (function declaration).
• Their data types are defined in the second statement.
Give one method for declaration of formal parameters.• Formal parameters can be declared using ANSI method .
• In this method the data types of the parameters are defined in the function declaration.
• The data types used can be integer, float, char, etc.
• Example: calsum(int x, int y, int z)
Here x,y,z are the formal parameters.
What is garbage value and how it can be avoided?
• If a function is not returning any specific value ,it returns data called garbage value.
return ; B
• In statement A a specified value ‘a’ is returned.
In statement B no specified value present so it returns a garbage value.
• To avoid the garbage value keyword void is placed before the function name.
void display ( )
Give the difference between call by value and call by reference.
• When a function is called it passes values of variables to called functions.
• This is called as call by value and we have access to formal parameters.
sum= calsum( a, b, c);
Here calsum is the function and a, b, c are the values passed.
• If instead of the values the addresses of value are passed it is called as call by reference.
• To pass values using call by reference pointers are used and we have access to actual parameters.
Which variables always contain whole numbers?
• Pointers are the variables which always contain data in the form of whole numbers.
• They store the address of other variables.
• They are declared as data type *name of variable.
• It also uses other operator ‘&’ which returns the address of the variable.
Here j is a variable that holds the address of other variable i.
• A function is called recursive if a statement within the function can call the same function.
• In circular definition it is the process of defining something in terms of itself.
• It is represented as rec( ).
• An if statement is used within recursive statement to avoid infinite loop.
rec ( int x)
if (x== 1)
return ( 1 );
return ( f );
Function to find the factorial of a number.
Can user defined functions be added to the library ?If yes, explain.• Yes, the user defined functions can be added to the library.
• Also different compilers provide different utilities to modify functions and for c compilers utility called “tlib.exe” (Turbo library) is used.
• Initially create the function and then compile the file using Alt f9.
• This file contains the code in machine language and then add file to the library using the command “ c:\.>tlib math.lib + c:\filename.obj “
• Declare the prototype of function in the header file.
• To include it in a program use syntax : #include “c:\\filename.h”.
Explain the automatic and static storage classes.• Automatic and static storage classes for variables defined uses memory as the storage.
• These classes are local to the block in which variables are defined.
• Automatic class uses the garbage value as the default initial value.
• Static class uses the default initial value as zero.
• These classes remain till the control remains within block in which the variable is defined.