C++ strings are different from C strings and have additional functionality. Some key differences are that C++ strings can be initialized without needing strcpy, concatenated using +, and their length checked using length() or size(). Memory for C++ strings is automatically allocated and handled, unlike in C where memory must be manually allocated and managed.

1. C++ Strings
Different from C strings

2. Flush Everything you knew about C
strings

3. Declare a string
#include<iostream>
using namespace std;
int main()
{
string a;
//Declare a string
cin>>a;
cout<<a<<endl;
}

4. Initialize a string
string a=“Welcome to strings”;

5. Inputing strings having spaces
string a;
getline(cin,a);

6. Copy a String
//No need for strcpy
string a,b;
cin<<a;
b=a;
cout>>b>>endl;

7. Concatenate two string
string a,b,c;
cin>>a>>b;
c=a+b;
//Is’nt life easy
cout<<c<<endl;

8. Length of a string
string a;
cin>>a;
cout<<a.length()<<endl;
cout<<a.size()<<endl;
//Be little careful the value is not integer

9. Reverse a String
Input – abcde
Output- edcba

10. Some String properties
• Strings are zero indexed just like arrays.
• Each individual element of a string is a
character.(char datatype)

11. Palindrome?

12. Memory
• Every variable you declare takes some amount
of memory
• Just think of memory as a free store and every
time you declare a variable you allocate some
space in that free store.
• Example Integer takes 4 bytes,Character takes
1 byte.

13. Do we need to memorize this?
• Use the sizeof() operator
• Tells you the number of bytes allocated to a
datatype or a variable
• Example-sizeof(
int)
char c;
sizeof(c);

14. Dynamic Memory Allocation
• Sometimes you do not the amount of memory
you would be needing.

15. The new operator

16. The delete operator

17. Example

18. Dynamic Memory allocation for arrays

19. You have been given a grid of n
rows of m integers. Input n and m
and dynamically allocate the array
and take the array as input and
print the grid as given.