package com.jk.ref; class Ref{ int temp=10; } public class RefDemo01 { public static void main(String[] args) { // TODO Auto-generated method stub Ref re=new Ref(); re.temp=20; System.out.println(re.temp); Ref1(re); System.out.println(re.temp); } public static void Ref1(Ref t){ t.temp=30; } }
package com.jk.ref;java
public class RefDemo02 {this
public static void main(String[] args) {spa
// TODO Auto-generated method stubcode
String st1="hello";get
System.out.println(st1);it
tell(st1);class
System.out.println(st1);方法
}im
public static void tell(String st2){static
st2="world";
}
}
package com.jk.ref; class Person{ private String name; private int age; public Person(String name,int age){ this(); this.name=name; this.age=age; } public Person(){ System.out.println("無參數構造方法"); } /** * @return the name */ public String getName() { return name; } /** * @param name the name to set */ public void setName(String name) { this.name = name; } /** * @return the age */ public int getAge() { return age; } /** * @param age the age to set */ public void setAge(int age) { this.age = age; } public void tell(){ System.out.println("name:"+getName()+" "+"age:"+getAge()); } } public class ThisDemo { public static void main(String[] args) { // TODO Auto-generated method stub Person per=new Person("zhangsnan",20); per.tell(); } }
package com.jk.ref; class Person{ public void tell(){ System.out.println(this); } } public class ThisDemo { public static void main(String[] args) { // TODO Auto-generated method stub Person per=new Person(); System.out.println(per); per.tell(); } }
java static關鍵字
一、使用static聲明屬性
static聲明全局屬性
二、使用static聲明方法
直接經過類名調用
三、注意點
使用static方法的時候,只能訪問static聲明的屬性和方法,而非static聲明的屬性和方法是不能訪問的。
package com.jk.ref; class People{ String name; private static String country="中國"; public People(String name){ this.name=name; } public void tell(){ System.out.println("name:"+name+" "+"country:"+country); } /** * @return the country */ public static String getCountry() { return country; } /** * @param country the country to set */ public static void setCountry(String country) { People.country = country; } } public class StaticDemo01 { public static void main(String[] args) { // TODO Auto-generated method stub People.setCountry("shanghai"); People ps1=new People("zhangsan"); //People.country="上海"; ps1.tell(); People ps2=new People("lisi"); // ps2.country="上海"; ps2.tell(); People ps3=new People("wangwu"); // ps3.country="上海"; ps3.tell(); } }
使用static方法的時候,只能訪問static聲明的屬性和方法,而非static聲明的屬性和方法是不能訪問的。
package com.jk.ref; public class StaticDemo02 { private static int i=10; public static void main(String[] args) { // TODO Auto-generated method stub System.out.println(i); tell(); } public static void tell(){ System.out.println("hello"); } }