#include"iostream"
using namespace std;
void display(){
int y=-2;
cout<<&y<<endl;
}
int main(){
int x=-1;
cout<<&x<<" ";
display();
return 0;
}

#include"iostream"
using namespace std;
void display(){
int y=-2;
cout<<&y<<endl;
}
void hien(){
display();
}
int main(){
int x=-1;
cout<<&x<<" ";
hien();
return 0;
}

#include"iostream"
#include"fstream"
using namespace std;
void ghifile(){
ofstream ptr("Doc.dat",ios::out|ios::binary);
for(int i=1;i<5;++i)
ptr.write((char*)&i,4);
ptr.close();
}
void docfile(){
int x=-1;
fstream ptr("Doc.dat",ios::in|ios::binary);
while(ptr){
ptr.read((char *)&x,4);
cout<<x<<endl;
}
ptr.seekg(0,ios::beg);
if(ptr.eof()) cout<<"error"<<endl;
ptr.close();
}
int main(){
ghifile();
docfile();
return 0;
}

1
2
3
4
4
error

#include"iostream"
using namespace std;
class person{
private:
char name[20];
int age;
public:
void nhap(){
cout<<"nhap ho va ten:";
cin.getline(name,20);
cout<<"nhap tuoi";
cin>>age;
}
void show(){
cout<<name<<" tuoi "<<age;
}
};
int main(){
person a;
a.nhap();
a.show();
return 0;
}

#include"iostream"
using namespace std;
struct person{
private:
char name[20];
int age;
public:
void nhap(){
cout<<"nhap ho va ten:";
cin.getline(name,20);
cout<<"nhap tuoi";
cin>>age;
}
void show(){
cout<<name<<" tuoi "<<age;
}
};
int main(){
person a;
a.nhap();
a.show();
return 0;
}

#include"iostream"
using namespace std;
class Foo{
int i;
public:
Foo(){
cout<<this<<endl;
}
};
int main(){
Foo foo[4];
return 0;
}

1 // hello_world-1.c
2
3 #include <stdio.h>
4
5 int main(void)
6 {
7 printf("hello world\n");
8
9 return 0;
10 }

$ gcc -W -Wall -c hello_world-1.c
$ gcc -o hello_world-1 hello_world-1.o

$ size hello_world-1 hello_world-1.o
text data bss dec hex filename
916 256 4 1176 498 hello_world-1
48 0 0 48 30 hello_world-1.o
$ objdump -h hello_world-1.o
hello_world-1.o: file format elf32-i386
Sections:
Idx Name Size VMA LMA File off Algn
0 .text 00000023 00000000 00000000 00000034 2**2
CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE
1 .data 00000000 00000000 00000000 00000058 2**2
CONTENTS, ALLOC, LOAD, DATA
2 .bss 00000000 00000000 00000000 00000058 2**2
ALLOC
3 .rodata 0000000d 00000000 00000000 00000058 2**0
CONTENTS, ALLOC, LOAD, READONLY, DATA
4 .note.GNU-stack 00000000 00000000 00000000 00000065 2**0
CONTENTS, READONLY
5 .comment 0000001b 00000000 00000000 00000065 2**0
CONTENTS, READONLY