Day10_java面向物件 static關鍵字詳解
阿新 • • 發佈:2020-11-26
static關鍵字詳解
package com.oop.demo07; public class Student { private static int age; //靜態變數 private double score; //非靜態變數 public void run(){ go(); } public static void go(){ System.out.println("hh"); } public static void main(String[] args) { go(); Student s1 = new Student(); System.out.println(Student.age); System.out.println(s1.score); System.out.println(s1.age); } }
package com.oop.demo07; public class Person { //2.賦初值~ { System.out.println("匿名程式碼塊"); } //1.只執行一次 static { System.out.println("靜態程式碼塊"); } //3 public Person(){ System.out.println("構造方法!"); } public static void main(String[] args) { Person person = new Person(); System.out.println("==============="); Person person1 = new Person(); } }
通過final修飾的類沒有子類
package com.oop.demo07;
//靜態匯入包~
import static java.lang.Math.random;
import static java.lang.Math.PI;
public class Test {
public static void main(String[] args) {
System.out.println(random());
System.out.println(PI);
}
}