// 动态申请内存， 指向一个未初始化的整型 int *pi = new int;

// pi指向一个整型值，初始化为0 int *pi = new int();

// value of i is 1024 int i(1024);

// pi指向1024 int *pi = new int(1024);

// value of  s is "99999" string s(5, '9');

// *ps is "999999" string *ps = new string(6, '9');

/*  只有使用new申请的内存，才能用delete来释放 */

int i = 100; int *pi = &i; double *pd = new double(100);

// error: pi 指向一个局部变量，没有使用new来申请内存 delete pi;

// ok delete pd;