关于sizeof && strlen

#include
#include
using namespace std;

enum MyEnum
{
a=0,
b=1,
EVO_MSG_REQUEST_IDENTIFIER_ALLOCATE = 3,
EVO_MSG_REPLY_IDENTIFIER_ALLOCATE = 4,

EVO_MSG_REQUEST_GRAPH_LIBRARY_QUERY = 5,
EVO_MSG_REPLY_GRAPH_LIBRARY_QUERY = 6

}MyEnum;

struct EvoVersion
{
char type;
char state;
char major;
char minor;
bool operator==(const EvoVersion & theVersion) const
{
return (type == theVersion.type
&& state == theVersion.state
&& major == theVersion.major
&& minor == theVersion.minor);
}
};

char m_CompName[128];
int main()
{

char *tmpBufMsg = new	char[100];
strcpy_s(tmpBufMsg,7, "hello");

cout << sizeof(tmpBufMsg) << endl;  //4
cout << strlen(tmpBufMsg) + 1 <<endl; //6

cout << sizeof(MyEnum) << endl;//4
cout << sizeof(a) << endl;//4


cout << sizeof(EvoVersion) << endl; //4
cout << sizeof(m_CompName) << endl; //128

unsigned int tt = 1;
cout << sizeof(tt) << endl; //4

unsigned long hh = 2;
cout << sizeof(hh) << endl; //4

system("pause");
return 1;

}

对sizeof的认知：

//对于非指针类型的数组，sizeof(数组名)长度是数组分配的大小，而不是数据类型所占的字节大小

char sz[] = "hello world!";
cout << "sizeof(sz)=" << sizeof(sz) << endl;      //13 带有结束符
cout << "sizeof(char)=" << sizeof(char) << endl;  //1个字节
cout << "sizeof sz=" << sizeof sz << endl;        //13
cout << "sz =" << sz << endl;                     //hello world!

char str[8];
cout << "sizeof(str)=" <<sizeof(str)<< endl;       //不是1 而是8
cout << "szieof(char)" << sizeof(char) << endl;    //1
cout << "str=" << str << endl;                     //烫烫烫烫烫烫烫烫

int a = 7;
cout << "a=" << a<<endl;                         //7
cout << "sizeof(a)=" << sizeof(a) << endl;            //4
cout << "sizeof(int)=" << sizeof(int) << endl;          //4





//指针类型的数据 为四个字节  不论是(char *)、（int *）还是（void *）都是四个字节
char* msg = new char[1024];
cout << "sizeof(char*)" << sizeof(char*) << endl;  //4
cout << "sizeof(msg)=" << sizeof(msg) << endl;     //4
cout << "msg=" << msg << endl;                     //1024个屯

int* msgTest = new int [1024];
cout << "sizeof(int*)" << sizeof(int*) << endl;          //4
cout << "sizeof(msgTest)=" << sizeof(msgTest) << endl;    //4
cout << "msgTest=" << msgTest << endl;       //0100BCA0 指向内存的地址

short i = 0;
cout << sizeof(short) << endl; //2
cout << sizeof(i) << endl; //2

bool flag = true;
cout << sizeof(bool) << endl; //1
cout << sizeof(flag) << endl; //1