c++中提取string中字符的方法

1.类似于使用数组
string a = “abcdef”;
int num = a.length();
for (int i = 0; i < num; ++i)
{
cout << a[i];
}
2.使用for循环
string a = “asdfa”;
for (char ch : a)
cout << ch;
cout << a.length();