C++基础知识记录---类型大小

C++中基础知识记录---类型大小

sizeof(Type)：

测试程序可以查看】：

int main(){
    /*int a[10] = { 10, 2, 3, 1, 2, 3 };
    int *p = a;
    cout << "a的大小" << sizeof(a) << endl;
    cout << "a[i]的大小" << sizeof(a[1]) << endl;
    cout << "指针变量p的大小" << sizeof(p) << endl;
    cout << "指针*p的大小" << sizeof(*p) << endl;*/
    /*char cv = 'a', *pcv = &cv;
    int i = 2;
    int *p;
    p = &i;
    p++;*/
    //测试不同type 类型指针变量＋1 地址会增加类型大小的多少指针；牵扯到不同类型指针变量开辟空间大小
    char cv = 'a', *pcv = &cv;//  pcv记录cv的地址；*pcv指针映射到具体的值
    cout << "pcv:" << pcv << " pcv+1: " << pcv + 1 << endl;
    short sv = 1, *psv = &sv;//2个字节
    cout << "psv:" << psv << " psv+1: " << psv + 1 << endl;
    int iv = 1, *piv = &iv;//4个字节
    cout << "piv:" << piv << " piv+1: " << piv + 1 << endl;
    long lv = 1, *plv = &lv;//4个字节
    cout << "plv:" << plv << " plv+1: " << plv + 1 << endl;
    long long llv = 1, *pllv = &llv;//8个字节
    cout << "pllv:" << pllv << " pllv+1: " << pllv + 1 << endl;
    float fv = 1.0, *pfv = &fv;//4个字节
    cout << "pfv:" << pfv << " pfv+1: " << pfv + 1 << endl;
    double dv = 1.0, *pdv = &dv;//8个字节
    cout << "pdv:" << pdv << " pdv+1: " << pdv + 1 << endl;
    long double ldv = 1.0, *pldv = &ldv;//8个字节
    cout << "pldv:" << pldv << " pldv+1: " << pldv + 1 << endl;
    //cout<<"pcv:"<<pcv<<" pcv+1: "<<pcv+1<<endl;   
    cout << endl;
    return 0;
}

 运行结果】