C v/s C++

1) Comments :- 

 'C' supports only block comment while C++ support block comment

  as well as line comment.

2) Type Casting :- 

 'C'       Style  :  (float)x         // C++ also support this style too.

  'C++'   Style  :  float(x)

3) Length of variable names :- 

ANSI 'C' allow to have any number of characters in the variable but 

consider only first 32 of them.

 'C++' also allow to have any number of charaters in the variable name 

with all of them being significant.

4) Data Declaration :- 

'C' strictly requires variables to declared at the beginning of the scope

 before the first executable statement, 

 While 'C++' allows to declered variable anywhere in the scope, also

at the place of its first use.

                for(int k=0;k<=rows;k++)

                {

                     for(int m=0;m<=cols;m++)

                     {

                     }

                 }

                 k=2;           // right b'cos k is declared outside of the scope

                 m=2;          // wrong b'cos m is declared inside the scope 

6) Type Compatibility :- 

'C++" is very strict with regard to type compatibility, 

while 'C'  is  not so strict.

                                            char x='A';

                                            int i,j,k;

 'C' treats character

  constant as integer      i=sizeof(char);

 'C++' treats charater      j=sizeof(x);

 constant as character

                                            k=sizeof('A'); 

7) Symbolic Constants :-

a) Similarities :-  

(i) Both 'C' and 'C++' use the keyword 'const' for declaring

 symbolic constants and in both 'C'