指针变量

/*
 * pointDemo.cpp
 *
 *  Created on: 2016年7月20日
 *      Author: zroad
 */
#include<iostream>
using namespace std;

void pointVar() {
    //变量j若未初始化，系统将随即给该变量赋值
    int i = 15, j, *p, *q;

    cout << "i=" << i << endl;
    cout << "j=" << j << endl;
    cout << "p=" << p << endl;
    cout << "q=" << q << endl;
    /*
     *  i=15
     j=1
     p=0x77a028e0
     q=0x1e
     */

    //指针即是指向变量的变量，其值为变量的内存地址
    p = &i; //p=0x22fe2c
    q = &j; //q=0x22fe28
    cout << "------------------" << endl;
    cout << "i=" << i << endl;
    cout << "j=" << j << endl;
    cout << "p=" << p << endl;
    cout << "q=" << q << endl;
    cout << "+++++++++++++++++" << endl;
    cout << "i=" << *p << endl;
    cout << "j=" << *q << endl;
}

void pointAndMem() {
    int *p = new int; //分配一片存储整数的内存区域，指针变量p存储其地址
    *p = 100;
    cout << "p=" << p << ";" << *p << endl;

    delete p; //此处使用delete释放分配的内存，否则后续重新对P赋值后导致内存不能释放
    p = new int;
    *p = 120;
    cout << "p=" << p << ";" << *p << endl;
}

int main() {
    pointVar();
    pointAndMem();

    return 0;
}