Basic of C++

Include headers

#include< headerfile>

Comma headers

iostream , istream , math , cctype , String

Name space

Using namespace std

Datatypes

int , char , float , double , void , bed

Comments

//comments text

/* Multiline comment text */

Arithmetic operator

+(Addition) , -(Subtraction) , *(Multiply) , /(Division)

Relational operators

<=(less than or equal to) , < (less than) , > (Greater than) , >= (greater than or equal to) , ==(equal to equal to)

Logical operator

׀׀ (logical OR) , && (logical AND) , ! (logical NOT)

Pointers

int *ptr         // Define Pointer

ptr = &var    // Ptr set to address var

var 2 = *ptr  // Set Var e, to value of var

For loop 

For (<initialize>; <Condition>)

{ <statement >;}

While loop

while (< condition >

{ <statement >;}

If else

if (< condition>)

      { <statement 1 > ; }

 else

 {  <statement 2 > ; }

Do while loop

do {< statement > ; }

    while (< condition>);

Array

//New 5 element Array

int my array [5];

//Array index starts at 0

//Access third element

my array [2] = var ;

Switch Statement

Switch  (<expression>)

}   

   case <constant 1 >;

      <statements sequence 1 > ;

         break ;

case  <constant  2 > ;

        <statement  sequence 2 > ;

           break ;

case < constant  n+1 > ;

         <statement sequence  n+1 > ;

            break ;

   {default :

         <Statement sequence  n > ; 

}

I/O operators

>>      //input operator

<<     // output operator

<in  >> var1 , var2 , var3 ;

cout <<"Test  : "<<var1 << var2 <<end ;

c in.get (char buffer.streamsize numchart );

File I/O

   fstream file

   file.open (filename "<<file mode constant >);

             //read and write like cin and cout

      file >> var ;

       file <<"Text " <<end ;

             //read entine line 

             getline (file , line );

         //Reading and writing binary data

           file.read (memory-black ,size );

           file.read (memory-black , size);

file.close ();

File mode Constant

ios ::in              // opens file for reading

ios ::out           //  opens file for writing

ios ::ate           //  seeks FOF ,I/O operations can occur

ios ::app          //   causes output to be appended at FOF

ios ::trunc       //    destroys previous contents

ios ::nocreate  //     causes open c) to fail if doesn't exist

ios ::noreplace  // causes open c) to fail if already exist

Function prototype 

<return-data-type><function-name> (permanent list>

   {body of function}

Class prototype 

class <class-name >

{

   public :

       //method-prototypes

    protected :

      //method-prototypes

    private :

     // method - prototypes

    // data - attributes                   }

Structure  prototype

struct <structure name >}

member - type 1 member-name 1;

member -type 2  member-name 2;

}      <object-name>;

Accessing data structure

//Access member variable from struct / class

mystruct.membervar 1 = var ;

//call class method

myclass.method 1(args);

//pointer to struct /class

mystructType       *ptr ;

 ptr  = &mystruct  ;

 ptr -> membervar1 = var ;