c++基础回顾

#include <iostream>

#include <vector>

#include <string>

int main(int argc, const char * argv[]) {

// insert code here...

std::cout << "Hello, World!\n";

int a=0;

std::cout <<(a==0?"a==0":"a!=0");

int b[10] = {10,3,3,3};

std::vector<int> c;

c.push_back(10);

c.push_back(40);

c.push_back(33);

int d=c[0];

int e=c[1];

int f=c[2];

std::cout<<d<<std::endl;

std::cout<<e<<std::endl;

std::cout<<f<<std::endl;

std::cout<<c.size()<<std::endl;

for (int i=0; i<c.size();i++) {

std::cout<<c[i]<<std::endl;

}

char str[128]="Hello World";

char *p="Hello World";

std::string s;

s="232sdsafdas912::";

s+="dsadsad[[";

return 0;

}

#include <iostream>

int main(int argc, const char * argv[]) {

int max(int x,int y);

int a,b,c;

std::cout<<"输入两个数字"<<std::endl;

std::cin>>a>>b;

c=max(a, b);

std::cout<<c;

}

int max(int x,int y){

int z;

if(x>y) z=x;

else z=y;

return z;

}

#include <iostream>

using namespace std;

class Student{

private:

int num;

int score;

public:

void setdata(){

cin>>num;

cin>>score;

}

void display(){

cout<<"num="<<num<<endl;

cout<<"score="<<score<<endl;

}

};

Student s1,s2;

int main(int argc, const char * argv[]) {

s1.setdata();

s1.display();

s2.setdata();

s2.display();

}

#include <iostream>

using namespace std;

class Complex{

public:

Complex(){real=0;imag=0;}

Complex(double r,double i){real=r;imag=i;}

Complex operator + (Complex &c2);

void display();

private:

double real;

double imag;

};

Complex Complex::operator+(Complex &c2){

Complex c;

c.real=real+c2.real;

c.imag=imag+c2.imag;

return c;

}

void Complex::display(){

cout<<"("<<real<<","<<imag<<"i)"<<endl;

}

int main(int argc, const char * argv[]) {

Complex c1(3,4),c2(5,-10),c3;

c3=c1+c2;

cout<<"c1=";

c1.display();

cout<<"c2=";

c2.display();

cout<<"c1+c2=";

c3.display();

return 0;

}

#include <iostream>

#include <fstream>

using namespace std;

int main(int argc, const char * argv[]) {

int a[10];

ofstream outfile("f1.txt",ios::out);

if(! outfile){

cerr<<"open error!"<<endl;

exit(1);

}

cout<<"enter 10 integer numbers:"<<endl;

for (int i=0;i<10;i++) {

cin>>a[i];

outfile<<a[i]<<" ";

}

outfile.close();

return 0;

}