diff --git "a/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo01.java" "b/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo01.java"
new file mode 100644
index 0000000000000000000000000000000000000000..3e5b4e6c7c266c5589016a7164ae8e5a19ef278a
--- /dev/null
+++ "b/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo01.java"
@@ -0,0 +1,38 @@
+
+public class Demo01 {
+	public static void main(String[] args) {
+		int[] array = {19, 28, 37, 46, 50};
+		
+		System.out.println("ÅÅÐò֮ǰ£º");
+		printArray(array);
+
+		System.out.println("ÅÅÐòÖ®ºó£º");
+		printArray(sortArray(array));
+	}
+
+	public static int[] sortArray(int[] arr) {
+		int num ;
+		for (int i = 0; i < arr.length-1; i++) {
+			for (int j = 0; j < arr.length-1-i; j++) {
+				if(arr[j]<arr[j+1]) {
+					num = arr[j+1];
+					arr[j+1]=arr[j];
+					arr[j] = num;
+				}
+			}
+		}
+		return arr;
+	}
+
+	public static void printArray(int[] arr) {
+		System.out.print("[");
+		for (int i = 0; i < arr.length; i++) {
+			if (i == arr.length - 1) {
+				System.out.print(arr[i]);
+			} else {
+				System.out.print(arr[i] + ",");
+			}
+		}
+		System.out.println("]");
+	}
+}
diff --git "a/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo02.java" "b/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo02.java"
new file mode 100644
index 0000000000000000000000000000000000000000..04bc8a81d1e081d135ea73f9646973ec3dfdd6a8
--- /dev/null
+++ "b/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo02.java"
@@ -0,0 +1,14 @@
+
+public class Demo02 {
+
+	public static void main(String[] args) {
+		int a = 10;
+		int b = 20;
+		int temp;
+		temp = a;
+		a = b;
+		b = temp;
+		System.out.println("a:"+a+"b:"+b);
+	}
+
+}
diff --git "a/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo03.java" "b/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo03.java"
new file mode 100644
index 0000000000000000000000000000000000000000..cab6db92e31ff2aeed0d418984f9a791c69195f0
--- /dev/null
+++ "b/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo03.java"
@@ -0,0 +1,13 @@
+import java.util.Random;
+
+public class Demo03 {
+
+	public static void main(String[] args) {
+		Random ran = new Random();
+		int num = ran.nextInt(9999);
+		int abc = ran.nextInt(999);
+		System.out.println(num + "" +abc);
+
+	}
+
+}
diff --git "a/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo04.java" "b/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo04.java"
new file mode 100644
index 0000000000000000000000000000000000000000..342f4043858d058a8a4d8ba5bb5fd79aae2dea35
--- /dev/null
+++ "b/\346\226\271\346\263\225\345\244\215\344\271\2402/\350\256\270\345\237\271\346\250\237/Demo04.java"
@@ -0,0 +1,52 @@
+import java.util.Random;
+
+public class Demo04{
+
+	public static void main(String[] args) {
+		Random ran = new Random();
+		int abc [] = new int [6]; 
+		for (int i = 0; i < abc.length; i++) {
+			abc [i]=ran.nextInt(100)+1;
+		}
+		ring(abc);
+		System.out.println();
+		ring(cing(abc));
+		
+
+	}
+	public static int[] cing(int[]abc){
+		for (int i = 0; i < abc.length-1; i++) {
+			for (int j = 0; j < abc.length-i-1; j++) {
+				if (abc[j]<abc[j+1]) {
+					int temp;
+					temp=abc[j+1];
+					abc[j+1]=abc[j];
+					abc[j]=temp;
+					
+					
+					
+				}
+				
+			}
+		}
+		
+		return abc;
+	}
+	
+	
+	public static void ring(int []num) {
+		for (int i = 0; i < num.length; i++) {
+			if (i==num.length-1) {
+				System.out.print(num[i]);
+			}else {
+				System.out.print(num[i]+",");
+				
+			}
+			
+
+		}
+		
+		
+	}
+
+}
\ No newline at end of file