鏈表

基本形式（依賴于引用傳遞和this調用當前對象）

class Node{
    private String data;   //要保存的數據
    private Node next;  //要保存的下一節點
    public Node(String data){    //保存相對應的數據
        this.data = data;
    }
    public void setNext(Node next){
        this.next = next;
    }
    public Node getNext(){
        return this.next;
    }
    public String getData(){
        return this.data;
    }
}
public class ListNode{
    public static void main(String []args){
        Node root = new Node("火車頭");
        Node n1 = new Node("車廂A");
        Node n2 = new Node("車廂B");
        root.setNext(n1);
        n1.setNext(n2);
        Node current = root;
        while(current != null){
            System.out.println(current.getData());
            current = current.getNext();
        }
    }
}

裝箱與拆箱

int與Integer

public class ListNode{
    public static void main(String []args){
        Integer obj = new Integer(10);
        int temp = obj.intValue();
        System.out.println(temp*2);
    }
}

double與Double

public class ListNode{
    public static void main(String []args){
        Double obj = new Double(10.2);
        Double temp = obj.doubleValue();
        System.out.println(temp*2);
    }
}

boolean與Boolean

public class ListNode{
    public static void main(String []args){
        Boolean obj = new Boolean(true);
        Boolean temp = obj.booleanValue();
        System.out.println(temp);
    }
}

自動拆箱與裝箱

public class ListNode{
    public static void main(String []args){
        Integer obj = 10;  //自動裝箱
        int temp = obj;    //自動拆箱
        obj++;
        System.out.println(temp*obj);
    }
}

與String對象一致

public class ListNode{
    public static void main(String []args){
        Integer obja = 10;  //自動裝箱
        Integer objb = 10;
        Integer objc = new Integer(10);
        System.out.println(obja == objc);
        System.out.println(obja.equals(objc));
    }
}

Object可以接收一切的引用數據類型

public class ListNode{
    public static void main(String []args){
        Object obj = 10;
        int temp = (Integer)obj;
        System.out.println(temp*2);
    }
}

double必須給以指定的格式

public class ListNode{
    public static void main(String []args){
        Double obj = 10;
        System.out.println(obj);
    }
}
F:\prac>javac ListNode.java
ListNode.java:3: 錯誤: 不兼容的類型: int無法轉換為Double
                Double obj = 10;
                             ^
1 個錯誤
---------------------------------------------------
public class ListNode{
    public static void main(String []args){
        Double obj = 10.2;
        System.out.println(obj);
    }
}

Boolean

public class ListNode{
    public static void main(String []args){
        Boolean flag = true;
        if(flag){
            System.out.println("Hello");
        }
    }
}

String與各個基本數據類型之間的轉換操作
一、public static int parseInt(String s)

//被轉換的數必須由數字組成
public class ListNode{
    public static void main(String []args){
        String str = "123";
        int temp = Integer.parseInt(str);
        System.out.println(temp*3);
    }
}

二、public static double parseDouble(String s)

public class ListNode{
    public static void main(String []args){
        String str = "1.3";
        double temp = Double.parseDouble(str);
        System.out.println(temp*3);
    }
}

三、public static boolean parseBoolean(String s)

//如果String的值不是true或false，則按false統一處理
public class ListNode{
    public static void main(String []args){
        String str = "true";
        boolean temp = Boolean.parseBoolean(str);
        if(temp){
            System.out.println("滿足條件");
        }else{
            System.out.println("不滿足條件");
        }
    }
}
F:\prac>java ListNode
滿足條件
---------------------------------------------------------
public class ListNode{
    public static void main(String []args){
        String str = "xfxhfdnxde";
        boolean temp = Boolean.parseBoolean(str);
        if(temp){
            System.out.println("滿足條件");
        }else{
            System.out.println("不滿足條件");
        }
    }
}
F:\prac>java ListNode
不滿足條件

String轉基本數據類型
一、任何基本數據類型與String類型使用了“+”操作后均變為String類型

public class ListNode{
    public static void main(String []args){
        int num = 100;
        String str = num+"";
        System.out.println(str.replaceAll("0","9"));
    }
} 

二、public static String valueOf(數據類型 變量) public static String valueOf(int i)

public class ListNode{
    public static void main(String []args){
        int num = 100;
        String str = String.valueOf(num);
        System.out.println(str.replaceAll("0","9"));
    }
}