quick guide

1.Is the folowing program correct or not? yes/no

main()
{
char *str1 = "United";
char * str2 = "Front";
char *str3;
str3 = strcat(str1, str2);
printf("\n %s", str3);
}

Ans: No, since what is present in memory beyond "united" is
not known and we are attaching "Front" at the end of "United",
thereby overwriting something, which is unsafe thing to do.

2.How would you improve the code in the above program?

Ans: main()
{
char str1[15] = "United";
char *str2 = "Front";
char *str3;
str3 = strcat(str1,str2);
printf("\n%s", str3);
}

3. Write a program to enter the two strings and compare them
without using any standard function. Determine whether the
strings are identical or not.
Also display the number of position where the characters are
different.

main()
{
static char sr[10], tr[10];
int diff = 0,i;
clrscr();
printf("\n enter the string");
gets(sr);
printf("enter the second string");
gets(tr);
for(i =0; i<10;i++)
{
if(sr[i] ==tr[i]);
continue;
else
{
printf("%c %c\n", sr[i],tr[i]);
diff++;
}
}
if(strlen(sr) == strlen(tr)&&diff == 0)
puts("\n The two strings are identical");
else
printf("\n The two strings are different
at %d places", diff);
getch();
}

output:
enter the string: BEST LUCK
enter the second string: GOOD LUCK
G B
O E
O S
D T

4.Write a program to concatenate two strings without the use
of standard library functions

main()
{
char name[50], fname[15], sname[15], lname[15];
int i,j,k;
printf("first name");
grts(fname);
printf("second name");
grts(sname);
printf("last name");
grts(lname);
for(i =0; fname[i]!='\0'; i++)
name[i]=fname[i];
name[i]=' ';
for(j =0; sname[j]!='\0'; j++)
name[i+j+1]=sname[i];
name[i+j+1]=' ';
for(k =0; lname[k]!='\0'; k++)
name[i+j+k+2]=lname[k];
name[i+j+k+2]='\0 ';
printf("\n\n");
printf("complete name after concatenation\n");
printf("%s", name);
getch();
}

output:
first name: MOHAN
second name:KARAMCHAND
last name: GANDHI
complete name after concatenation
MOHAN KARAMCHAND GANDHI

5.Write a program to display reverse of a string without using
standard library functions.

main()
{
char text[15];
int i = 0;
printf("enter the string");
gets(text);
while(text[i[!='\0')
{
printf("\n 5c is stored at location %u", text[i],&text[i])
i++;
}
strrev(text);
printf("reverse string");
printf("%s",text);
i =0;
while(text[i]!='\0')
{
printf("\n %c is stored at location %u",text[i], &text[i]);
i++;
}
}

output:
enter string:ABC
A is stored at location 4054
B is stored at location 4055
C is stored at location 4056
reverse string:CBA
C is stored at location 4054
B is stored at location 4055
A is stored at location 4056

6.Write a program to find the number of words in a given
statement . Exclude spaces between them.

main()
{
char text[30];
int count = 0,i = 0;
printf("enter the line of text");
printf("give one space after each word");
gets(text);
while(text[i++]!='\0')
if(text[i]==32 || text[i]=='\0')
cout++;
printf("The number of words in line = %d\n", count);
}

output:
enter the line of text
give one space after each words
read books
The number of words in line = 2