From scratch to learn Java-10. Make full use of existing objects, java-10 make full use

From scratch to learn Java-10. Make full use of existing objects, java-10 make full use

1. Design of superclass and subclasses;
2. Establish an inheritance level;
3. Override method.

Program StringLister: displays a series of strings alphabetically to the screen using array lists and special for loops. These strings come from an array and command line parameters.

 1 package com.jsample; 2  3 import java.util.*; 4  5 public class StringLister { 6     String[] names = { "Spanky", "Buckwheat", "Daria", 7         "Stymie", "Marianne", "Scotty", "Tommy", "Chubby" }; 8  9     public StringLister(String[] moreNames){10         Vector<String> list = new Vector<String>();11         for (int i = 0; i < moreNames.length; i++){12             list.add(moreNames[i]);13         }14         Collections.sort(list);15         for (String name : list){16             System.out.println(name);17         }18     }19 20     public static void main(String[] args){21         StringLister lister = new StringLister(args);22     }23 }

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Output:

Buckwheat
Chubby
Daria
Marianne
Scotty
Spanky
Stymie
Tommy

 

Program PointTester: Programs that use Point, Point3D, and Point4D objects and move them on the screen.

 1 package com.jsample; 2  3 import java.awt.*; 4  5 public class PointTester { 6     public static void main(String[] args){ 7         Point objcet1 = new Point(11,22); 8         Point3D object2 = new Point3D(7,6,64); 9         Point4D object3 = new Point4D(12,56,73,90);10 11         System.out.println("The 2D point is located at (" + objcet1.x12                 + ", " + objcet1.y + ")");13         System.out.println("\tIt's being moved to (4,13)");14         objcet1.move(4,13);15         System.out.println("The 2D point is now at (" + objcet1.x16             + ", " + objcet1.y + ")");17         System.out.println("\tIt's being moved -10 units on the x "18             + "and y axes");19         objcet1.translate(-10,-10);20         System.out.println("The 2D point ends up at (" + objcet1.x21             + ", " + objcet1.y + ")\n");22 23         System.out.println("The 3D point is located at (" + object2.x24             + ", " + object2.y + ", " + object2.z + ")");25         System.out.println("\tIt's being moved to (10, 22, 71)");26         object2.move(10,22,71);27         System.out.println("The 3D point is now at (" + object2.x28             + ", " + object2.y + ", " + object2.z +")");29         System.out.println("\tIt's being moved -20 units on the x,y "30             + "and z axes");31         object2.move(-20,-20,-20);32         System.out.println("The 3D point ends up at (" + object2.x33             + ", " + object2.y + ", " + object2.z + ")\n");34 35         System.out.println("The 4D point is located at (" + object3.x36                 + ", " + object3.y + ", " + object3.z + ", " + object3.t + ")");37         System.out.println("\tIt's being moved to (9, 1, 7, 4)");38         object3.move(9,1,7,4);39         System.out.println("The 4D point is now at (" + object3.x40                 + ", " + object3.y + ", " + object3.z + ", " + object3.t + ")");41         System.out.println("\tIt's being moved 20 units on the x,y "42                 + "and z axes");43         object3.move(20,20,20,20);44         System.out.println("The 4D point ends up at (" + object3.x45                 + ", " + object3.y + ", " + object3.z + ", " + object3.t + ")");46     }47 }

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Subordinate class:

Point -- java. awt.

Point3D: records the object's 3D coordinates, moves the object to the new coordinate, and moves the three coordinates to a specific distance.

 1 package com.jsample; 2  3 import java.awt.*; 4  5 public class Point3D extends Point{ 6     public int z; 7  8     public Point3D(int x, int y, int z){ 9         super(x,y);10         this.z=z;11     }12 13     public void move(int x, int y, int z){14         this.z += z;15         super.translate(x,y);16     }17 }

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Point4D: records the four-dimensional coordinates of the object, moves the object to the new coordinate, and moves the four coordinates to a specific distance.

 1 package com.jsample; 2  3 public class Point4D extends Point3D{ 4     public int t; 5  6     public Point4D(int x, int y, int z, int t){ 7         super(x,y,z); 8         if (t < 0) 9             return;10         this.t = t;11     }12 13     public void move(int x, int y, int z, int t){14         this.z += z;15         this.t += t;16         super.translate(x,y);17     }18 }

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Output:

The 2D point is located at (11, 22)
It's being moved to (4, 13)
The 2D point is now at (4, 13)
It's being moved-10 units on the x and y axes
The 2D point ends up at (-6, 3)

The 3D point is located at (7, 6, 64)
It's being moved to (10, 22, 71)
The 3D point is now at (17, 28,135)
It's being moved-20 units on the x, y and z axes
The 3D point ends up at (-3, 8,115)

The 4D point is located at (12, 56, 73, 90)
It's being moved to (9, 1, 7, 4)
The 4D point is now at (21, 57, 80, 94)
It's being moved 20 units on the x, y and z axes
The 4D point ends up at (41, 77,100,114)