c++基础学习之string

 

//学习使用string类 2013-10-18 lingc
#include <iostream>
#include <string>//include this head file <string>
using namespace std;

int main()
{
    string myString1;
    myString1 = "hello world,i am lingc!";// can no use the ' ' 
    string myString2(myString1,5,12);// begin at index 5, and count 12 elements
    string myString3(4,'z');
    cout<<"how to use the class of string,by lingc at 2013-10-18"<<endl;
    cout<<"myString1 is "<< myString1 <<endl;
    cout<<"myString2 is "<< myString2 <<endl;
    cout<<"myString3 is ""<< myString3 <<"" and its length is "
            << myString3.length() <<endl;

    //combine the string
    string comString = myString1 + " " + "i am so sleepy.";
    
    cout << comString <<endl;
    //the follow is wrong 不能用+来连接字符串字面量
    //string comString2 = " " + "so sleepy " + myString1;
    //corect is to the right
    string comString2 = " " + ("so sleepy " + myString1);
    cout<< comString2 << endl;

    return 0;
}

可以使用string[] 来访问字符串中的字符:

#include <iostream>
#include <string>
using namespace std;

int main()
{
    string mystring = "hello world.";
    cout<< mystring <<endl;
    for (size_t i=0; i<mystring.length(); i++)
    {
        mystring[i] = toupper(mystring[i]);
    }
    cout<< mystring <<endl;
    return 0;
}