c++ append用法

转载：https://blog.csdn.net/wxn704414736/article/details/78551886

append函数是向string的后面追加字符或字符串。 
1).向string的后面加C-string 
string s = “hello “; const char *c = “out here “; 
s.append(c); // 把c类型字符串s连接到当前字符串结尾 
s = “hello out here”; 
2).向string的后面加C-string的一部分 
string s=”hello “；const char *c = “out here “; 
s.append(c,3); // 把c类型字符串s的前n个字符连接到当前字符串结尾 
s = “hello out”; 
3).向string的后面加string 
string s1 = “hello “; string s2 = “wide “; string s3 = “world “; 
s1.append(s2); s1 += s3; //把字符串s连接到当前字符串的结尾 
s1 = “hello wide “; s1 = “hello wide world “; 
4).向string的后面加string的一部分 
string s1 = “hello “, s2 = “wide world “; 
s1.append(s2, 5, 5); ////把字符串s2中从5开始的5个字符连接到当前字符串的结尾 
s1 = “hello world”; 
string str1 = “hello “, str2 = “wide world “; 
str1.append(str2.begin()+5, str2.end()); //把s2的迭代器begin()+5和end()之间的部分连接到当前字符串的结尾 
str1 = “hello world”; 
5).向string后面加多个字符 
string s1 = “hello “; 
s1.append(4,’!’); //在当前字符串结尾添加4个字符! 
s1 = “hello !!!!”;