理清楚4个目标
父类引用(“名”)父类对象(“实”)子类引用子类对象
理清楚几个操作
// 父类
public class parent{}// 子类
public class sun{}父类引用指向父类对象
parent p1 new parent();子类引用指向子类对象
son s1 …
Java官方文档[1]的解释 public static int parseInt(String s) throws NumberFormatException Parses the string argument as a signed decimal integer. The characters in the string must all be decimal digits, except that the first character may be an ASCII minus…