JAVA基础2-class基础

package helloworldapp;

public class class_basics {
    /** field */
    private int cadence; //节奏
    private int gear;
    private int speed;
    /** constructor */
    public class_basics(int startCadence,int startSpeed, int startGear){
        this.gear = startGear;
        this.speed = startSpeed;
        this.cadence = startCadence;

        ID = ++number_class_baiscs_instantiated; // assign new id to new object and increase global counting by 1
    }
    /** get,set method */
    public int getGear() {
        return gear;
    }
    public void setGear(int gear){
        this.gear = gear;
    }
    public void setCadence(int cadence) {
        this.cadence = cadence;
    }
    public int getCadence() {
        return cadence;
    }

    public int getSpeed() {
        return speed;
    }
    public void setSpeed(int speed) {
        this.speed = speed;
    }

    /** overloading method */
    public void draw(String s){}
    public void draw(int i){}

    /** array as parameter */
    public String print(String[] mystrings){
        return "";
    }

    /** arbitrary number of arguments */
    public String print(int... myints){ // 和 int[] myints 作为参数效果一样
        int a = myints[1];
        int length = myints.length;
        System.out.printf("%s: %d","the length of input array is",length);
        return "";
    }

    /** field multiple in one row */
    private int x,y,radius;

    /** explicit constructor invocation 显式调用另外的constructor */
    public class_basics(int startCadence){ //好处是可以提供默认生成/简略生成的方式
        this(startCadence,0,1);
    }
    public class_basics(int startCadence,int startSpeed){
        this(startCadence,startSpeed,1);
    }

    /** access level 不同attribute的权限：
     * Modifier	    Class Package Subclass    World
     * public	    Y	    Y	     Y	        Y
     * protected    Y	    Y	     Y	        N
     * no modifier  Y	    Y	     N	        N
     * private	    Y	    N	     N	        N
     * */

    /** class variable (static)*/
    private int ID;
    private static int number_class_baiscs_instantiated = 0;

    /** class method (static)*/
    public static int getNumber_class_baiscs_instantiated(){
        return number_class_baiscs_instantiated;
    }

    /** constant */
    static final double PI = 3.41592653589793;

    /** initializing fields */
    public static int capacity = 10;

    /** static initialization blocks */
    static{
        int firstint = 1;
    }

    /** nested classes */
    class innerClass{}
    /** acces from main:
     *  class_basics cb = new class_basics();
     *  class_basics.innerClass ic = cb.new innerClass();
     * */
    static class staticNestedClass{}


    /** local class: define a class in for-loop or a method */
    private static void validatePhoneNumber(String num1,String num2){
        final int numLen = 10;
        final String regularExp = "[^0-9]";
        class PhoneNum{
            String formattedPhoneNumber = null;
            PhoneNum(String num){
                String currentNum = num.replaceAll(regularExp,"");
            }
        }
    }

    /** anonymous class: define a class in instantiation */
    interface helloworld{
        public void greet();
        public void greetSomeone(String someone);
    }
    helloworld englishGreeting = new helloworld() {
        String name = "idiot";
        @Override
        public void greet() {
            greetSomeone("nice 2 meet u");
        }
        @Override
        public void greetSomeone(String someone) {
            name = someone;
            System.out.print("hello"+name);
        }
    };
    helloworld germanGreeting = new helloworld() {
        @Override
        public void greet() {
            greetSomeone("Herr XXX");
        }
        @Override
        public void greetSomeone(String someone) {
            System.out.print("Hallo"+someone);
        }
    };

    /** lambda expression: the anonymous method without name*/
    interface IntegerMath{
        int operation(int a ,int b);
    }
    public int doOpeartion(int a, int b, IntegerMath m){
        return m.operation(a,b);
    }
    private void lambdatest(){
        IntegerMath addition = (a,b) -> a+b;
        // addition.operation(1,2);
        System.out.println(doOpeartion(1,2,addition));
    }

    /** enum */
    public enum Day {
        SUNDAY, MONDAY, TUESDAY, WEDNESDAY,
        THURSDAY, FRIDAY, SATURDAY
    }
    public class EnumTest{
        Day day;
        public EnumTest(Day day) {
            this.day = day;
        }
    }




}