使用 new 和 delete 动态地分配和释放内存

new 将返回指向一个指针，指向分配的 内存，否则将引发异常。使用 new 时，需要指定要为哪种数据类型分配内存：
Type* Pointer = new Type; // request memory for one element

需要为多个元素分配内存时，还可指定要为多少个元素分配内存：
Type* Pointer = new Type[numElements]; // request memory for numElements

因此，如果需要给整型分配内存 并释放，可使用如下语法：
int pointToAnInt = new int; // get a pointer to an integer
delete Pointer;
多个元素分配的内存
int pointToNums = new int[10]; // pointer to a block of 10 integers
delete[] Pointer;

使用 new 分配内存，并使用 delete 释放它们

#include <iostream>
using namespace std;
int main(){
    int* points_to_an_age = new int;
    cout << "Enter your dog's age ";
    cin  >> *points_to_an_age;
    cout << "Age " << *points_to_an_age << " is stored at " << points_to_an_age << endl;
    delete points_to_an_age;
    return 0;
}

使用 new[…]分配内存，并使用 delete[]释放它们

#include <iostream>
#include <string>
using namespace std;
int main(){
    cout << "How many integers shall i reserve memory for? " << endl;
    int numEntries = 0;
    cin  >> numEntries;
    int* myNumbers = new int[numEntries];
    cout << "Memory is stored at " << myNumbers << endl;
    delete[] myNumbers;
    return 0;
}