C program to accept string from user and convert all lower case letters into upper case and vice-versa.

Write a ‘C’ program to accept string from user and convert all lower case letters into upper case and vice-versa.

#include<stdio.h>
#include<conio.h>
void main()
{
  char name[80];
  int l,i;
  clrscr();
  printf("Enter the String");
  gets(name);
  l=strlen(name);
  for(i=0;i<l;i++)
  {
    if(islower(name[i]))
    {
      printf("%c",toupper(name[i]));
    }
    else  if(isupper(name[i]))
    {
      printf("%c",tolower(name[i]));
    }
    else
    {
      printf("%c",name[i]);
    }
  }
  getch();
 }

C program to calculate sum of two m*n matrices and store the result in 3rd matrix.

Write a ‘C’ program to calculate sum of two m*n matrices and store the result in 3rd matrix.

#include<stdio.h>
#include<conio.h>
void main()
{
int a[3][3],b[3][3],c[3][3],i,j;
clrscr();
printf("enter the matrix element");
for(i=0;i<=2;i++)
{
for(j=0;j<=2;j++)
{
scanf("%d",&a[i][j]);
}
}
for(i=0;i<=2;i++)
{
for(j=0;j<=2;j++)
{
scanf("%d",&b[i][j]);
}
}
for(i=0;i<=2;i++)
{
for(j=0;j<=2;j++)
{
c[i][j]=a[i][j]+b[i][j];
}
}
for(i=0;i<=2;i++)
{
printf("\n");
for(j=0;j<=2;j++)
{
printf("%d\t",c[i][j]);
}
}
getch();
}