C++字符串string类常用操作详解(一)【初始化、遍历、连接】

水深无声 2021-11-10 17:24 149阅读 0赞

#include <iostream>
    #include "string"
     
    using namespace std;
     
    //字符串初始化
    void strInit()
    {
    	cout << "字符串初始化:"  <<endl;
     
    	string s1 = "abcdefg";	//初始化方式1
    	string s2("abcdefg");	//初始化方式2
    	string s3 = s2;			//通过拷贝构造函数 初始化s3
    	string s4(7,'s');		//初始化7个s的字符串
     
    	cout << "s1 = "<< s1 << endl;
    	cout << "s2 = "<< s2 << endl;
    	cout << "s3 = "<< s3 << endl;
    	cout << "s4 = "<< s4 << endl;
    }
     
    //字符串遍历
    void strErgo()
    {
    	cout << "字符串遍历:"  <<endl;
     
    	string s1 = "abcdefg";	//初始化字符串
    	
    	//通过数组方式遍历
    	cout << "1、通过数组方式遍历:"  <<endl;
    	for (int i = 0; i < s1.length(); i++)
    	{
    		cout << s1[i] << " ";
    	}
    	cout << endl;
     
    	//通过迭代器遍历
    	cout << "2、通过迭代器遍历:"  <<endl;
    	for(string::iterator it = s1.begin(); it!= s1.end(); it++)
    	{
    		cout << *it << " ";
    	}
    	cout << endl;
     
    	//通过at()方式遍历
    	cout << "3、通过at()方式遍历:"  <<endl;
    	for (int i = 0; i < s1.length(); i++)
    	{
    		cout << s1.at(i) << " ";		//此方式可以在越界时抛出异常
    	}
    	cout << endl;
    }
     
    //字符指针和字符串的转换
    void strConvert()
    {
    	cout << "字符指针和字符串的转换:"  <<endl;
    	string s1 = "abcdefg";	//初始化字符串
     
    	cout << "string转换为char*:"  <<endl;
    	//string转换为char*
    	cout << s1.c_str() <<endl;	//s1.c_str()即为s1的char *形式
     
    	cout << "char*获取string内容:"  <<endl;
    	//char*获取string内容
    	char buf[64] = {0};
    	s1.copy(buf, 7);//复制7个元素
    	cout << buf <<endl;
    }
     
    //字符串连接
    void strAdd()
    {
    	cout << "字符串连接:"  <<endl;
     
    	cout << "方式1:"  <<endl;
    	string s1 = "123";
    	string s2 = "456";
    	s1 += s2;
    	cout << "s1 = "<< s1 << endl;
     
    	cout << "方式2:"  <<endl;
    	string s3 = "123";
    	string s4 = "456";
    	s3.append(s4);
    	cout << "s3 = "<< s3 << endl;
    }
    int main()
    {
    	//初始化
    	strInit();
    	cout << endl;
    	//遍历
    	strErgo();
    	cout << endl;
    	//字符指针类型和字符串转换
    	strConvert();
    	cout << endl;
    	//字符串连接
    	strAdd();
    	cout << endl;
    	system("pause");
    	return 0;
    }