hello,world
#include <iostream>
using namespace std;
int main()
{
cout << "Hello world!" << endl;
return 0;
}
getline
成员函数getline()是从输入流中读取一行字符，读到终止符时会将’\0’存入结果缓冲区中 [4]，作为输入的终止。终止符可以是默认的终止符，也可以是定义的终止符。函数的语法结构是：
getline(<字符数组chs>，<读取字符的个数n>，<终止符>)
#include <iostream>
using namespace std;
int main()
{
string name;
string welcomeMessage;
cout << "Hello world!" << endl;
cin>>name;
cout << "Hi!" <<name<< endl;
getline(cin,welcomeMessage,'#');
cout<<welcomeMessage<<endl;
return 0;
}
Hello world!
lisi
Hi!lisi
you are good student!
#
you are good student!
Process returned 0 (0x0) execution time : 11.410 s
Press any key to continue.
std::cin
可同时接收多个数据输入，每个数据用空格分隔！
Hello world!
name age
lisi 29
Hi!lisi 29
Process returned 0 (0x0) execution time : 3.817 s
Press any key to continue.
#include <iostream>
using namespace std;
int main()
{
string name;
int age;
int temp;
string welcomeMessage;
cout << "Hello world!" << endl;
cout<<"name age"<<endl;
cin>>name>>age;
cout << "Hi!" <<name<<" "<<age<<endl;
return 0;
}
引用与指针
- 标量
100
100
88
99
Process returned 0 (0x0) execution time : 1.819 s
Press any key to continue.
#include <iostream>
using namespace std;
int main()
{
int a;
int &a1=a;
int *a2=&a;
cin>>a;
cout<<a<<endl;
a1=88;
cout<<a<<endl;
*a2=99;
cout<<a<<endl;
return 0;
}
- 数组指针
#include <iostream>
using namespace std;
int main()
{
int a[]{1,2,3,4,5,6,7,8};
int *s=a;
for (int *p=a;p<s+8;p++){
cout<<p<<":"<<*p<<endl;
}
}
#include <iostream>
using namespace std;
int main()
{
int a[]{1,2,3,4,5,6,7,8};
for (int *p=a;p<a+8;p++){
cout<<p<<":"<<*p<<endl;
}
}
1
2
3
4
5
6
7
8
Process returned 0 (0x0) execution time : 0.126 s
Press any key to continue.
- 数组的引用
下面的程序是错误的
#include <iostream>
using namespace std;
int main()
{
int a[]{1,2,3,4,5,6,7,8};
for (int (&p)[8]=a;p<a+7;p++){
cout<<*p<<endl;
}
}
错误如下
正确的写法只能如下：
#include <iostream>
using namespace std;
int main()
{
int a[]{1,2,3,4,5,6,7,8};
int (&p)[8]=a;
for (int i=0;i<8;i++){
cout<<p[i]<<endl;
}
}
如果一定要用指针，只能考虑另外使用一个指针变量了，因为引用指向的内容可以更改，但引用本身的指向是不能更改，只读的。
#include <iostream>
using namespace std;
int main()
{
int a[]{1,2,3,4,5,6,7,8};
int (&p)[8]=a;
for (int *p1=p;p1<a+8;p1++){
cout<<*p1<<endl;
}
}
函数
#include <iostream>
using namespace std;
void goThrough(int (&arr)[8]){
for (int *p1=arr;p1<arr+8;p1++){
cout<<*p1<<endl;
}
}
int main()
{
int a[]{1,2,3,4,5,6,7,8};
goThrough(a);
}
更改数组元素
#include <iostream>
using namespace std;
void goThrough(int (&arr)[8]){
for (int *p1=arr;p1<arr+8;p1++){
cout<<*p1<<endl;
}
for (int *p1=arr;p1<arr+8;p1++){
*p1*=10;
}
for (int *p1=arr;p1<arr+8;p1++){
cout<<*p1<<endl;
}
}
int main()
{
int a[]{1,2,3,4,5,6,7,8};
goThrough(a);
}
1
2
3
4
5
6
7
8
10
20
30
40
50
60
70
80
Process returned 0 (0x0) execution time : 0.130 s
Press any key to continue.