Programming Questions

Q:

How would you dynamically allocate a 2-D array of integers?

Answer

#include "alloc.h"


#define MAXROW 3


#define MAXcol 4


main()


{


        int *p, i, J;


        p = (int *) malloc (MAXROW * MAXCOL * sizeof (int));


         for ( i=0; i < MaxROW ; i++)


         {


                for (j=0; j < MAXCOL ; j++)


                { 


                      p [ i * MAXCOL + j] = i;


                       printf ( "%d", p [i * MAXCOL + j] );


                 }


                  printf ("\n");


          }


}

Report Error

View answer Workspace Report Error Discuss

Subject: Programming

0 3476
Q:

In the following code can we declare a new typedef name emp even though struct employee has not been completely defined while using typedef? < Yes / No>

typedef struct employee *ptr;

struct employee

{

       char name[20];

        int age;

        ptr next;

};

Answer

Yes

Report Error

View answer Workspace Report Error Discuss

Subject: Programming

0 3393
Q:

Point out the error, if any, in the following program.

#include "stdio.h"

main()

{

      unsigned char;

       FILE *fp;

       fp = fopen ("trail", "r");

       while (( ch = getc (fp)) ! = EOF)

               printf ("%c", ch);

       fclose (fp);

}  

Answer

EOF has been defined as #define EOF -1 n the file "stdio.h" and an unsigned char ranges from 0 to 255 hence when EOF is read from the file it cannot be accommodated in ch. Solution is to declare ch as an int.

Report Error

View answer Workspace Report Error Discuss

Subject: Programming

1 3332
Q:

If the following structure is written to a file using fwrite(), can fread() read it back successfully?

struct emp

{

    char *n;

    int age;

};

struct emp e = { "Sujay",15};

FILE *fp;

fwrite (&e, sizeof (e), 1, fp);

Answer

No, since the structure contains a char pointer while writing the structure to the disk using fwrite() only the value stored in the pointer n would get written. When this structure is read back the address would be read back but it is quite unlikely that the desired string would be present at this address in memory

Report Error

View answer Workspace Report Error Discuss

Subject: Programming

0 3241
Q:

What value does read() return when it has reached the end of a file?

A) 1 B) -1
C) 0 D) None
 
Answer & Explanation Answer: B) -1

Explanation:

It returns -1

Report Error

View Answer Report Error Discuss

Filed Under: Programming

1 3221
Q:

Point out the error, if any, in the following program.

# include "stdio.h"

main()

{

     FILE *fp;

     char str[80];

     fp = fopen ("trail", "r");

     while (!feof (fp))

    {

           fgets (str, 80, fp);

           puts (str);

     }

     fclose (fp);

}

Answer

The last line from the file "trial" would be read twice. To avoid this, ues:


       While ( fgets (str, 80, fp) ! = NULL)


               puts (str);

Report Error

View answer Workspace Report Error Discuss

Subject: Programming

0 3168
Q:

Indicate what would the SWAP macro be expanded to on preprocessing. Would the code compile?

#define SWAP (a, b, c ) (c t; t = a, a = b, b = t; )

main()

{

    int x = 10, y = 20;

    SWAP (x, y, int );

    printf ( " %d%d ", x, y);

}

Answer

( int t ; t = a, a = b, b = t ;);


This code won't compile since declaration of t cannot occur within parentheses.


 

Report Error

View answer Workspace Report Error Discuss

Subject: Programming

0 3096
Q:

public static void main string[] args Meaning is?

Answer

Here in this declaration public static void main string[] args, each keyword has its importance.


 


1. public - Here public is an access specifier which allows the main method to be accessible everywhere.


 


2. static - static helps the main method to get loaded without getting called by any instance/object.


 


3. void - void clarifies that the main method will not return any value.


 


4. main - It's the name of the method.


 


5. String[] args - Here we are defining a String array to pass arguments at the command line. args is the variable name of the String array.

Report Error

View answer Workspace Report Error Discuss

8 3051