Dynamic memory allocation (C ++)

• Dynamic memory allocation in C ++

1. C ++, dynamic memory allocation using the new keyword
2. C ++ dynamic memory allocation is performed based on the type of
3. delet keywords for memory release

. 1   . 1  // variable application 
2   2 the Type = * pointer new new the Type;
 . 3   . 3  // .... 
. 4   . 4  Delete pointer;
 . 5   . 5   
. 6   . 6  // array application 
. 7   . 7 the Type = * pointer new new the Type [N];
 . 8   . 8  // .... 
9   9  the Delete [] pointer;

 

10 #include " stdio.h " 
. 11  int main ()
 12 is  {
 13 is          // new new initialization can 
14          int * P = new new  int ( 100 );
 15          // * P =. 5; 
16          * * = P + P . 5 ;
 . 17          the printf ( " P = P% \ n- " , P);
 18 is          the printf ( " * D P =% \ n- " , * P);
 . 19          Delete P;
 20 is          P = new new  int [ 10];
 21 is          for ( int I = 0 ; I < 10 ; I ++ )
 22 is          {
 23 is                 P [I] = I + . 1 ;
 24                 the printf ( " P [% D] =% D \ n- " , I, P [I] );
 25          }
 26 is          Delete P;
 27          return  0 ;
 28 } 
The result:

pi@raspberrypi:~ $ g++ main.cpp
pi@raspberrypi:~ $ ./a.out
p=0x15c4058
*p=105
p[0]=1
p[1]=2
p[2]=3
p[3]=4
p[4]=5
p[5]=6
p[6]=7
p[7]=8
p[8]=9
p[9]=10

• The difference between the new keyword and malloc function

1. new keywords are part of C ++
2. malloc is a function provided by the C library
3. In particular new types of memory allocation units of
4. malloc byte memory allocation units
5. When applying a single type of new variables may be initialized
6. malloc do not have the memory initialization properties