string中erase用法总结

函数原型

 // erase 删除 从pos开始的n个字符  
    MyString& MyString::erase(size_t pos,size_t n)  
    {  
        if((pos+n)>strLength)  
        {  
            throw Outofbond();  
        }  
        char *p_old = p_str;  
        strLength -= n;  
        p_str = new char[strLength+1];  
        for(size_t i=0;i<pos;i++)  
        {  
            p_str[i] = p_old[i];  
        }  
        for(size_t i=pos;i<strLength;i++)  
        {  
            p_str[i] = p_old[i+n];  
        }  
        *(p_str+strLength) = '\0';  
        return *this;  
    } 

用法一

erase(pos, n); 删除从第pos开始的第n个字符

#include<iostream>
using namespace std;
int main()
{
   string str = "don't go gentle into the good night";
   str.erase(0, 6);
   cout << str;//go gentle into the good night
}

用法二

erase(pos)；pos为迭代器，删除pos处的一个字符

#include<iostream>
#include<string>
using namespace std;
int main()
{
	string str = "don't go gentle into the good night";
	string::iterator pos = str.begin() + 4;
	str.erase(pos);
	cout << str;//don' go gentle into the good night
	
}

用法三

erase(first, last); first和last都是迭代器，删除从first开始到last之间的字符

#include<string>
#include<iostream>
using namespace std;
int main()
{
	string str = "don't go gentle into the good night";
	str.erase(str.begin() + 8, str.end() - 20);
	cout << str;//don't go into the good night
}