Programming Questions

While extracting a float argument using va_arg we should have useed 

c = va_arg (ptr, double)

An explicit intent explicitly defines the activity the developer wishes to start. 

Script code :

Intent myIntent = new Intent(this, MyNewActivity.class);

startActivity(myIntent);

rand()  returns a random number

random()  returns a random number in a specified range

srand()  initialise a random number generator with a given seed value

randomize()   initializes a random number generator with a random value based o time.

int a = 1, b , dummy;

a > 10 ? b = 20 : dummy =1;

Note that the following would not have worked:

a > 10 ? b = 20 : ;;

As against malloc(), calloc() needs two arguments, the number of elements  to be allocated and the size of each element. For example,

 p = (int *) calloc (10, sizeof (int));

would allocate space for a 10- integer array. Additionally, calloc() would also set each of this element with a value 0.

Thus the above call to calloc() is equivalent to:

p = (int *) malloc (10 * sizeof (int));

memset (p, 0, 10 * sizeof( int ));

The coding or scrambling of data so that humans cannot read them is known as encryption.

Yes, using the realloc() function as shown below:

main()

{

        int *p;

        p = ( int *) malloc (20) ;

        t = p;

        t = (int *) realloc ( p, 40);

        if ( t == NULL )

        Printf (" Cannot reallocate, leaves previous allocated region unchanged ");

       else

       {

              if ( p ==t )

              ;  / * the array expanded at the same region */

             else

            { 

                 free ( p ); / * deallocate the original array */

                 p = t;  /* set p to newly allocated region */

             }

      }

}  

#include "string.h"

#include "stdlib.h"

struct stud

{

       int rollno;

       int marks;

       char name[30];

};

int sort_m (struct stud *, struct stud *);

int sort_name (struct stud *, struct stud *);

int sort_marks (struct stud *, struct stud *);

main()

{

static struct stud ss[] = {

                                            { 15, 96, "Akshay" },

                                            { 2, 97, "Madhuri" },

                                            { 8, 85, "Aishvarya" },

                                            { 10, 80, "Sushmita" }

                                   };

int x,w;

clrscr();

w = sizeof (struct stud);

printf ('\nIn order of roll numbers:");

qsort (ss, 4, w, sort_rn);

for(x=0; x<4;x++)

     printf ("\n%d%s%d", ss[x].rollno, ss[x].name,ss[x].marks);

printf("\n\nIn order of names:");

qsort(ss, 4, sort_name);

for (x=0; x<4;x++)

      printf("\n%d%s%d",ss[x].rollno, ss[x].name,ss[x].marks);

printf("\n\nIn order of marks:");

qsort(ss,4,w,sort_marks);

for (x=0;x<4;x++)

      printf ("\n%d%s%d",ss[x].rollno,ss[x].name,ss[x].marks);

}

int sort_rn (struct stud *t1, struct stud *t2)

{

     return (t1->rollno-t2->rollno);

}

int sort_name (struct stud *t1, struct stud *t2)

{

     return (strcmp(t1->name,t2->name));

}

int sort_marks (struct stud *t1, struct stud *t2)

{

     return (t2->marks-t1->marks);

}