今天就这样吧，吃多了嚼不烂

.gitignore

@@ -1,4 +1,6 @@
 ### IntelliJ IDEA ###
+.idea/
+./*.iml
 out/
 !**/src/main/**/out/
 !**/src/test/**/out/

src/class4/VaruableDemo2.java

@@ -0,0 +1,14 @@
+package class4;
+
+public class VaruableDemo2 {
+    public static void main(String[] args) {
+        printLiteral();
+    }
+    public static void printLiteral()
+    {
+        char ch = 'A';
+        System.out.println(ch + 1);
+        char ch2 = 'a';
+        System.out.println(ch2 + 1);
+    }
+}

src/class5/VariableDemo3.java

@@ -0,0 +1,31 @@
+package class5;
+
+public class VariableDemo3 {
+    public static void main(String[] args) {
+        printVariable();
+    }
+    public static void printVariable(){
+        byte b = 10;
+
+        short s = 20;
+        int i = 30;
+        long l = 40;
+        float f = 1.1F;
+        double d = 2.2;
+
+        char c = 'a';
+
+        boolean bool = true;
+
+        String str = "hello";
+        System.out.println(str);
+        System.out.println(bool);
+        System.out.println(c);
+        System.out.println(d);
+        System.out.println(f);
+        System.out.println(l);
+        System.out.println(i);
+        System.out.println(s);
+        System.out.println(b);
+    }
+}