string

string对象的size() 肯定大于等于capacity()

插入和追加insert(),append()

替换 replace()

 

 

 

string b("china");
59 cout << "the string china" <<" size is " << b.size() << " capacity " << b.capacity() << endl;
60 b.reserve(100);
61 cout << "the string china" <<" size is " << b.size() << " capacity " << b.capacity() << endl;

 

结果是

the string china size is 5 capacity 5
the string china size is 5 capacity 100

 

try{
64 string c("1234");
65 c.at(4);
66 }catch(exception &ex1){
67 cout << ex1.what() << endl;
68 }

其中at()会产生异常，而[]则不会产生任何异常，只是让程序猿自行决定