Decimal to octal conversion using function

Program:

#include<stdio.h>
void dec2oct(int);
int main()
{
int dec;
printf("Enter Positive Integer Number: ");
scanf("%d",&dec);
dec2oct(dec);
return 0;
}
void dec2oct(int m)
{
    int oct[10],i=0,j;
    while(m>0)
    {
    oct[i]=m%8;
    m=m/8;
    i++;
}
for(j=i-1;j>=0;j--)
{
printf("%d",oct[j]);
}
}

Output:

Decimal to hex conversion using function

Program:

#include<stdio.h>
void dec2hex(int);
int main()
{
int dec;
printf("Enter Positive Integer Number: ");
scanf("%d",&dec);
dec2hex(dec);
return 0;
}
void dec2hex(int m)
{
    int i=0,j;
    char hex[10],store[16]={'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
    while(m>0)
    {
    hex[i]=store[m%16];
    m=m/16;
    i++;
}
for(j=i-1;j>=0;j--)
{
printf("%c",hex[j]);
}
}

Output:

Decimal to binary conversion using function

Program:

#include<stdio.h>
void dec2bin(int);
int main()
{
int dec;
printf("Enter Positive Integer Number: ");
scanf("%d",&dec);
dec2bin(dec);
return 0;
}
void dec2bin(int m)
{
    int bin[10],i=0,j;
    while(m>0)
    {
    bin[i]=m%2;
    m=m/2;
    i++;
}
for(j=i-1;j>=0;j--)
{
printf("%d",bin[j]);
}
}

Output:

Exchange values using call by reference

Program:

#include<stdio.h>
void exch(int *a,int *b)
{
  int temp;
  temp=*a;
  *a=*b;
  *b=temp;
  printf("Inside Function::\n");
  printf("a=%d b=%d\n",*a,*b);
}
int main()
{
int x,y;
printf("Enter value of x and y: \n");
scanf("%d%d",&x,&y);
exch(&x,&y);
    printf("From main Function::\n");
    printf("x=%d y=%d\n",x,y);
    return 0;
}

Output:

Exchange values using call by value

Program:

#include<stdio.h>
void exch(int a,int b)
{
  int temp;
  temp=a;
  a=b;
  b=temp;
  printf("Inside Function::\n");
  printf("a=%d b=%d\n",a,b);
}
int main()
{
int x,y;
printf("Enter value of x and y: \n");
scanf("%d%d",&x,&y);
exch(x,y);
     printf("From main Function::\n");
     printf("x=%d y=%d\n",x,y);
     return 0;
}

Output: