Languages-C & C Plus Plus [3i Infotech Placement]: Sample Questions 338 - 339 of 354

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Question 338

C & C Plus Plus
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Describe in Detail

Essay▾

What is the output of the following program?

  1. main ()
  2. {
  3.     structstudent
  4.     {
  5.         charname[30];
  6.         structdatedob;
  7.     }stud;
  8.     structdate
  9.     {
  10.         intday, month, year;
  11.     };
  12.     scanf ( “%s%d%d%d” ,stud. Rollno, &student. Dob. Day, &student. Dob. Month, &student. Dob. Year);
  13. }

Explanation

Compiler Error: Undefined structure “date”

In the program

Table Shows the Program
struct student

{

char name [30] ;

struct date dob;

} stud;

  • Inside the struct definition of ‘student’ the member of type struct date is given.
  • The compiler doesn՚t have the definition of date structure (forward reference is not allowed in C in this case)
  • So, it issues an error

Question 339

C & C Plus Plus
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Describe in Detail

Essay▾

For the following C program

  1. #defineAREA (x) (3.14 ⚹x ⚹x)
  2. main ()
  3. {
  4.     floatr1 =6.25, r2 =2.5, a;
  5.     a =AREA (r1);
  6.     printf ( “Areaofthecircleis %f”, a);
  7.     a =AREA (r2);
  8.     printf ( “Areaofthecircleis %f” ,a);
  9. }

What is the output?

Explanation

  • In the program
Table Showing the Program
#define AREA (x) (3.14 ⚹ x ⚹ x)
  • Define the area () function
float r1 = 6.25, r2 = 2.5, a;
  • Define the float variable r1 = 6.25, r2 = 2.5 and a variable
a = AREA (r1) ;
  • Thus when the preprocessor runs,
Here a = AREA (6.25) ;

a = (3.14 ⚹ 6.25 ⚹ 6.25)

a = 122.656250

printf ( “Area of the circle is % f” , a) ;
  • Printf prints the area of the circle as 122.656250
a = AREA (r2) ;Similarly, a = AREA (2.5) ;

a = (3.14 ⚹ 2.5 ⚹ 2.5)

a = 19.625000

printf ( “Area of the circle is % f” , a) ;
  • Printf print the Area of the circle is 19.625000

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