diff --git a/GuiCalculator.java b/GuiCalculator.java
index 13b41b30b97fe4fdcfe932978a609e914fb8969c..294dd93a9f6e7aadd66cd0a181473d64077c4449 100644
--- a/GuiCalculator.java
+++ b/GuiCalculator.java
@@ -16,149 +16,169 @@ import javax.swing.JTextField;
 
 public class GuiCalculator {
 
-	public static void main(String[] args) {
-		CalculatorUI ui=new CalculatorUI("VSCode GitPlugin GuiCalculator");
-		ui.setVisible(true);
-		ui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
-	}
+  public static void main(String[] args) {
+    CalculatorUI ui = new CalculatorUI("VSCode GitPlugin GuiCalculator");
+    ui.setVisible(true);
+    ui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+  }
+}
+
+class CalculatorUI extends JFrame {
+
+  private JTextField textField = new JTextField("0");
+
+  private JPanel panel = new JPanel(new GridLayout(5, 4));
+  private JButton bt11 = new JButton("7");
+  private JButton bt12 = new JButton("8");
+  private JButton bt13 = new JButton("9");
+  private JButton bt14 = new JButton("/");
+  private JButton bt21 = new JButton("4");
+  private JButton bt22 = new JButton("5");
+  private JButton bt23 = new JButton("6");
+  private JButton bt24 = new JButton("*");
+  private JButton bt31 = new JButton("1");
+  private JButton bt32 = new JButton("2");
+  private JButton bt33 = new JButton("3");
+  private JButton bt34 = new JButton("-");
+  private JButton bt41 = new JButton("0");
+  private JButton bt42 = new JButton(".");
+  private JButton bt43 = new JButton("=");
+  private JButton bt44 = new JButton("+");
+  private JButton bt51 = new JButton("%");
+  private JButton bt52 = new JButton("!");
+  private JButton bt53 = new JButton("~");
+  private JButton bt54 = new JButton("^");
+  JButton jb[] = {
+    bt11,
+    bt12,
+    bt13,
+    bt14,
+    bt21,
+    bt22,
+    bt23,
+    bt24,
+    bt31,
+    bt32,
+    bt33,
+    bt34,
+    bt41,
+    bt42,
+    bt43,
+    bt44,
+    bt51,
+    bt52,
+    bt53,
+    bt54,
+  };
+
+  class MyHandler implements ActionListener {
+
+    String str = "";
+
+    @Override
+    public void actionPerformed(ActionEvent e) {
+      JButton source = (JButton) e.getSource();
+
+      if (source == bt43) {
+        str = str + "= " + CalcString.getRes(str);
+        textField.setText(str);
 
+        int res = JOptionPane.showConfirmDialog(
+          panel,
+          "Calculated, Goon ?",
+          "",
+          JOptionPane.YES_NO_OPTION
+        );
+        if (res == JOptionPane.YES_OPTION) {
+          str = "";
+          textField.setText("0");
+        } else System.exit(0);
+      } else {
+        str = str + source.getText();
+        textField.setText(str);
+      }
+    }
+  }
+
+  public CalculatorUI(String title) {
+    super(title);
+    this.ComponentInit();
+    MyHandler myHandler = new MyHandler();
+    this.ListenerAdd(myHandler);
+    this.setLocation(300, 200);
+    this.setSize(600, 450);
+  }
+
+  private void ComponentInit() {
+    this.add(textField, BorderLayout.NORTH);
+    textField.setPreferredSize(new Dimension(300, 80));
+    textField.setHorizontalAlignment(JTextField.RIGHT);
+    textField.setFont(new Font("楷体", Font.PLAIN, 32));
+    textField.setEditable(false);
+
+    this.add(panel, BorderLayout.CENTER);
+    panel.setPreferredSize(new Dimension(300, 350));
+    for (int i = 0; i < 20; i++) {
+      jb[i].setFont(new Font("楷体", Font.BOLD, 32));
+      panel.add(jb[i]);
+    }
+  }
+
+  private void ListenerAdd(MyHandler myHandler) {
+    for (int i = 0; i < 20; i++) {
+      jb[i].addActionListener(myHandler);
+    }
+  }
 }
 
-class CalculatorUI extends JFrame
-{
-	private JTextField textField=new JTextField("0");
-	
-	private JPanel panel=new JPanel(new GridLayout(5,4));
-	private JButton bt11=new JButton("7");
-	private JButton bt12=new JButton("8");
-	private JButton bt13=new JButton("9");
-	private JButton bt14=new JButton("/");
-	private JButton bt21=new JButton("4");
-	private JButton bt22=new JButton("5");
-	private JButton bt23=new JButton("6");
-	private JButton bt24=new JButton("*");
-	private JButton bt31=new JButton("1");
-	private JButton bt32=new JButton("2");
-	private JButton bt33=new JButton("3");
-	private JButton bt34=new JButton("-");
-	private JButton bt41=new JButton("0");
-	private JButton bt42=new JButton(".");
-	private JButton bt43=new JButton("=");
-	private JButton bt44=new JButton("+");
-	private JButton bt51=new JButton("%");
-	private JButton bt52=new JButton("!");
-	private JButton bt53=new JButton("~");
-	private JButton bt54=new JButton("^");
-	JButton jb[]={bt11,bt12,bt13,bt14,bt21,bt22,bt23,bt24,
-		bt31,bt32,bt33,bt34,bt41,bt42,bt43,bt44,bt51,bt52,bt53,bt54};
-	
-	class MyHandler implements ActionListener
-	{
-		String str="";
-		
-		@Override
-		public void actionPerformed(ActionEvent e) {
-			JButton source=(JButton) e.getSource();
-			
-			if(source==bt43)
-			{
-				str=str+"= "+CalcString.getRes(str);
-				textField.setText(str);
-				
-				int res=JOptionPane.showConfirmDialog(panel, "Calculated, Goon ?", "",JOptionPane.YES_NO_OPTION);
-				if(res==JOptionPane.YES_OPTION)
-				{
-					str="";
-					textField.setText("0");
-				}
-				else
-					System.exit(0);
-					
-			}
-			else
-			{
-				str=str+source.getText();		
-				textField.setText(str);
-			}	
-		}	
-	}
-	public CalculatorUI(String title)
-	{
-		super(title);
-		this.ComponentInit();
-		MyHandler myHandler=new MyHandler();
-		this.ListenerAdd(myHandler);
-		this.setLocation(300, 200);
-		this.setSize(600, 450);
-	}
-	
-	private void ComponentInit()
-	{
-		this.add(textField,BorderLayout.NORTH);
-		textField.setPreferredSize(new Dimension(300,80));
-		textField.setHorizontalAlignment(JTextField.RIGHT);
-		textField.setFont(new Font("楷体",Font.PLAIN,32));
-		textField.setEditable(false);
-		
-		this.add(panel,BorderLayout.CENTER);
-		panel.setPreferredSize(new Dimension(300,350));
-		for(int i=0;i<20;i++){
-			jb[i].setFont(new Font("楷体",Font.BOLD,32));
-			panel.add(jb[i]);
-		}
-		
-	}
-
-	private void ListenerAdd(MyHandler myHandler)
-	{
-		for(int i=0;i<20;i++){
-			jb[i].addActionListener(myHandler);
-		}
-	}
-	
+class CalcString {
+
+  public static double getRes(String str) {
+    String s = "";
+    double n1 = 0, n2, res = 0;
+    char op = 0;
+
+    for (int i = 0; i < str.length(); i++) {
+      if (
+        str.charAt(i) != '+' &&
+        str.charAt(i) != '-' &&
+        str.charAt(i) != '*' &&
+        str.charAt(i) != '/' &&
+        str.charAt(i) != '%'
+      ) {
+        s = s + str.charAt(i);
+      } else {
+        n1 = Double.parseDouble(s);
+        op = str.charAt(i);
+        s = "";
+      }
+    }
+    n2 = Double.parseDouble(s);
+
+    switch (op) {
+      case '+':
+        res = n1 + n2;
+        break;
+      case '-':
+        res = n1 - n2;
+        break;
+      case '*':
+        res = n1 * n2;
+        break;
+      case '/':
+        if (0 == n2) {
+          System.out.println("Error:/0");
+          res = 0;
+          break;
+        }
+        res = n1 / n2;
+        break;
+      case '%':
+        res = (int) n1 % (int) n2;
+        break;
+      default:
+    }
+
+    return res;
+  }
 }
-class CalcString
-{
-	public static double getRes(String str)
-	{
-		String s="";
-		double n1 = 0,n2,res = 0;
-		char op = 0;
-		
-		for(int i=0;i<str.length();i++)
-		{
-			if(str.charAt(i)!='+'&&str.charAt(i)!='-'&&str.charAt(i)!='*'&&str.charAt(i)!='/'&&str.charAt(i)!='%')
-			{
-				s=s+str.charAt(i);
-			}
-			else
-			{
-				n1=Double.parseDouble(s);
-				op=str.charAt(i);
-				s="";
-			}
-		}
-		n2=Double.parseDouble(s);
-		
-		switch (op) {
-		case '+':
-			res = n1 + n2;
-			break;
-		case '-':
-			res = n1 - n2;
-			break;
-		case '*':
-			res = n1 * n2;
-			break;
-		case '/':
-			res = n1 / n2;
-			break;
-		case '%':
-			res = (int)n1 % (int)n2;
-			break;
-		default:
-		}
-		
-		return res;
-	}
-}
\ No newline at end of file