Method of assigning a one-dimensional dynamic array or two-dimensional dynamic array and learning new method or vector

Let's start with an appetizer.

1 //dynamically allocating storage space using new2 3#include <iostream>4 usingstd::cout;5 6 intMain ()7 {8 //1th Way9 int*a=New int;Ten*a=1; Onecout<<"the result of dynamically allocating storage space using the first method is: \ n" A<<"*a="<<*a<<Std::endl; - DeleteA//releasing dynamic storage space - //2nd Way the int*b=New int(2); -cout<<"the result of dynamically allocating storage space using the first method is: \ n" -<<"*b="<<*b<<Std::endl; - Deleteb//releasing dynamic storage space + //3rd Way - int*C; +C=New int(3); Acout<<"the result of dynamically allocating storage space using the first method is: \ n" at<<"*c="<<*c<<Std::endl; - DeleteC//releasing dynamic storage space -  - //Creating arrays Dynamically - float*d=New float[3];//difference 1 new Type () and 2 new type [quantity]
One is to create an object from a constructor function
One is to create a dynamic array but not initialize if the built-in type has a default constructor
Most need to construct the initialization separately again -d[0]=3; ind[1]=6; -d[2]=8; tocout<<"d[0]="<<d[0]<<Std::endl; +D=d+1;//the fundamental difference between an array name and a pointer -cout<<"d[0]="<<d[0]<<Std::endl; thed=d-1; *cout<<"d[0]="<<d[0]<<Std::endl; $ Delete[] D;//releasing dynamic storage spacePanax Notoginseng return 0; -}

The result of dynamically allocating storage space using the first method is:
*a= 1
The result of dynamically allocating storage space using the first method is:
*b= 2
The result of dynamically allocating storage space using the first method is:
*c= 3
D[0]= 3
D[0]= 6
D[0]= 3

Above for the results of the implementation of their own want Ah!!!

new A pointer array
For a pointer to Class A, you can write this, not just new, but also the constructor of a.

A *P = new A();

But for a new pointer array, we can write this:

A **P = new A *[10];//这里是创建了10个A类型的指针 返回的是指针的地址

But we haven't made any construction yet? Here can not forget the construction AH!!!!

for(int i=0; i<10; i++){ p[i] = new A();}

Another problem is releasing:

for(int i=0; i<10; i++){ delete p[i];//为什么不是delete[]p[i]}delete [] p;

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Method of assigning a one-dimensional dynamic array or two-dimensional dynamic array and learning new method or vector