CASE CONVERSION IN A STRING - USING LOGIC

#include<iostream.h>

#include<conio.h>

#include<string.h>

char strng[50];

int len, n;

void cmpltcnvrsion(char strng[50])

{

  for(int i=0 ; i<len ; i++)

  {

    if((97<=int(strng[i]))&&(int(strng[i])<=122))

      cout<<char(int(strng[i])-32);

    else if((65<=int(strng[i]))&&(int(strng[i])<=90))

      cout<<char(int(strng[i])+32);

    else

      cout<<strng[i];

  }

}

void capital(char strng[50])

{

  for(int i=0 ; i<len ; i++)

  {

    if((97<=int(strng[i]))&&(int(strng[i])<=122))

      cout<<char(int(strng[i])-32);

    else

      cout<<strng[i];

  }

}

void small(char strng[50])

{

  for(int i=0 ; i<len ; i++)

  {

    if((65<=int(strng[i]))&&(int(strng[i])<=90))

      cout<<char(int(strng[i])+32);

    else

      cout<<strng[i];

  }

}

void main()

{

  clrscr();

  cout<<"Enter a string :\n";

  cin.getline(strng,50);

  len=strlen(strng);

  cout<<"\n\nChoose the type of conversion : \n 1>Complete conversion \n 2>ALL CAPITAL \n 3>all small \nEnter your choice : ";

  cin>>n;

  switch(n)

  {

    case 1  : cmpltcnvrsion(strng);

    break;

    case 2  : capital(strng);

    break;

    case 3  : small(strng);

    break;

  }

  getch();

}

.................................................................

OUTPUT: (click to enlarge the image)