char c[] = "abc"; cout<<sizeof(c)<<endl;//输出4 cout<<strlen(c)<<endl;//输出3
字符数组系统会自动在字符串常量自动加一个‘\0’
C++ sizeof的使用总结
http://blog.csdn.net/candyliuxj/article/details/6307814
C语言变量的类型和存储位置
http://blog.csdn.net/chenjin_zhong/article/details/12027615
