c++ 用new后delete，而继续输出指针后果

 1 #include<iostream>
 2 #include<cstring>
 3  #include <string.h>
 4 
 5  int main(){
 6  
 7  int *a =new int[100];
 8  for(int i=0;i<100;i++){a[i]=i;}
 9  char *b;
10  delete []a;
11  for(int i=0;i<1000000;i++){
12 b=new char [100];
13 b="dfdf";}
14  
15   for(int i=0;i<100;i++){cout<<a[i]<<endl;}
16   cout<<endl<<a;
17     
18  }