Aim: To implement a program for following string operations:

• Length of String.
• String Concatenation.
• Substring (provide start index and length)
• Find character at given index.
• Find index of first occurrence of a given character.
• Reverse string.

Code:                      

class String

{

            char str[50];

            public:

            String();

            void getdata();

            int length1();

            void concat(String s);

            String substring(int ind, int len);

            char charAt(int ind);

            int indexOf(char ch);

            String reverse();

            void display();

};

void String::display()

{

            cout<

}

void String::getdata()

{

            gets(str);

}

String::String()

{

            strcpy(str,"");

}

int String::length1()

{

            int l;

            l=strlen(str);

            return (l);

}

void String::concat(String s)

{

            strcat(str,s.str);

}

String String::substring(int ind, int len)

{

            int l,x,m;

            char su[50];

            String sub;

            strcpy(sub.str,"");

            for(x=ind,m=0;x<=len+1;x++,m++)

            {

                        su[m]=str[x];

            }

            su[m]='\0';

            strcpy(sub.str,su);

            return (sub);

}

char String::charAt(int ind)

{

            char c=' ';

            int l=strlen(str);

            if(ind>l)

                        cout<<"Position out of Bounds";

            else

                        c=str[ind];

            return (c);

}

int String::indexOf(char ch)

{

            int x=1;

            while(str[x]!=ch && str[x]!='\0')

                        x++;

            if(str[x]!=ch)

                        return (-1);

            else

                        return (x);

}

String String::reverse()

{

            String s;

            strcpy(s.str,str);

            strrev(s.str);

            return (s);

}

void main()

{

            clrscr();

            String s1,s2,s3,s4;

            cout<<"Enter string 1:";

            s1.getdata();

            cout<<"\n\nEnter string 2:";

            s2.getdata();

            char ch='o';

            int l=s1.length1();

            cout<<"\n\nLength of string: '";

            s1.display();

            cout<<" 'is "<

            s1.concat(s2);

            cout<<"\n\nAfter concatenation:";

            s1.display();

            int ind=2, len=4;

            cout<<"\n\nStart Index="<

            s3.display();

            char c=s1.charAt(ind+4);

            cout<<"\n\nCharacter at Index: "<

            int i=s1.indexOf(ch);

            cout<<"\n\nIndex of '"<

            s4=s1.reverse();

            cout<<"\n\nReverse of \n\t'";

            s1.display();

            cout<<"'\n\t\tis \n\t";

            s4.display();

            getch();

}

Output:

Enter string 1: Ankit Goyal is

Enter string 2: a student of VESIT.

Length of string: 'Ankit Goyal is ' is 14

After concatenation: Ankit Goyal is a student of VESIT.

Start Index=2

Length of Substring=4

Substring: kit

Character at Index: 6 is 'G'

Index of 'o' is: 7

Reverse of

        'Ankit Goyal is a student of VESIT.'

                is

        .TISEV fo tneduts a si layoG tiknA