这篇文章主要讲解了Java中如何转换父类和子类,内容清晰明了,对此有兴趣的小伙伴可以学习一下,相信大家阅读完之后会有帮助。
一、父类引用强转成为子类引用
package learn20180720; public class People { private String name; private Integer age; private Double height; public People(){ this.name = ""; this.age = 0 ; this.height = 0.0; } public People(String name, Integer age, Double height) { super(); this.name = name; this.age = age; this.height = height; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public Double getHeight() { return height; } public void setHeight(Double height) { this.height = height; } public void tellObjectName(People p) { System.err.println(p.name); } public void sayInformation() { System.err.println("我的名字叫做:"+this.name+"我的年龄是:"+this.age+"我的身高是"+this.height); } }
package learn20180720; public class Chinese extends People{ private String country; public Chinese(){ super(); country = ""; } public Chinese(String aname,Integer aage,Double aheight) { super(aname,aage,aheight); this.country = "中国"; } public String getCountry() { return country; } public void setCountry(String country) { this.country = country; } public void sayInformation() { // TODO Auto-generated method stub System.err.println("我的名字叫做:"+this.getName()+" 我的年龄是:"+this.getAge()+" 我的身高是:"+this.getHeight()+" 我的国家是:"+this.country); } }
package learn20180720; public class TestPeCh { public static void main(String[] args) { // TODO Auto-generated method stub People p1 = new Chinese(); Chinese c1 = (Chinese)p1; } }
可以看到,p1无法访问子类中的特有的方法(父类引用可以访问子类中重写父类中的方法),但是强转成为子类类型的引用c1之后,c1就可以访问子类中所有的方法啦。
package learn20180720; public class TestPeCh { public static void main(String[] args) { // TODO Auto-generated method stub People p1 = new People(); Chinese c1 = (Chinese)p1; } }
报错了!
看完上述内容,是不是对Java中如何转换父类和子类有进一步的了解,如果还想学习更多内容,欢迎关注亿速云行业资讯频道。
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