c++ 学习笔记（二）

#include <iostream>

int main(){
    //指定数组大小
    int arr1[5];
    arr1[0] = 12;
    //根据赋值获取确定数组实际大小
    int arr[] = {1,2,3,4,5,6,7,8,10,9};

    //获取数组长度
    int count = sizeof(arr)/sizeof(arr[0]);

    for(int i = 0;i<count;i++){
        std::cout << arr[i] <<std::endl;
    }

    std::cout << "arr1的值:" << arr1[0];
    return 0;
}

type *var-name;

#include <iostream>

int main ()
{
   int a = 3;
   int *p;
   p = &a;
   std::cout<< p;

   return 0;
}

#include <iostream>

int main ()
{
   int *p;
   int a[] = {1,2,3,4,5,6};
   //方式一
   p = a;
   //方式二
   p = &a[0];
   std::cout<< p;

   return 0;
}

#include <iostream>

int main ()
{
    int *p;
    int a[] = {1,2,3,4,5,6};
    p = a;
    std::cout << *p; //输出1
    p++;
    std::cout << *p; //输出2
   return 0;
}

#include <iostream>
using namespace std;

int main ()
{
   int a = 100;
   int& m = a;
   //其实m只是a的一个别名，他们指向相同的内存地址
   cout << &m <<endl;
   cout << &a;
   return 0;
}

#include <iostream>
using namespace std;

int arr[] = {1,2,3,4,5,6};

int& setValue(int i){
    return arr[i];
}

int main ()
{
   cout << "调用函数前arr[1]：" << arr[1] <<endl; //调用函数前arr[1]：2