Write a stack based calculator program in Java that implements GUI. Solution imp

Question

Write a stack based calculator program in Java that implements GUI.

Explanation / Answer

import java.awt.*; import java.awt.event.*; import javax.swing.*; import java.util.*; class Calculator2 extends JFrame implements ActionListener { private static final long serialVersionUID = 1L; JButton btn1 = new JButton("1"); JButton btn2 = new JButton("2"); JButton btn3 = new JButton("3"); JButton btn_add = new JButton("+"); JButton btn4 = new JButton("4"); JButton btn5 = new JButton("5"); JButton btn6 = new JButton("6"); JButton btn_sub = new JButton("-"); JButton btn7 = new JButton("7"); JButton btn8 = new JButton("8"); JButton btn9 = new JButton("9"); JButton btn_mult = new JButton("*"); JButton btn0 = new JButton("0"); JButton btn_dot = new JButton("."); JButton btn_del = new JButton("DEL"); JButton btn_div = new JButton("/"); JButton btn_lpr = new JButton("("); JButton btn_rpr = new JButton(")"); JButton btn_pow = new JButton("^"); JButton btn_equ = new JButton("="); JTextArea txt = new JTextArea(); String str_number = ""; public Calculator2() { JFrame frame = new JFrame("Simple Java Caculator"); frame.setSize(320,420); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setResizable(false); frame.setVisible(true); frame.setLayout(new GridLayout(2,1)); JPanel HeadPanel = new JPanel(); JPanel NumberPanel = new JPanel(); JPanel LabelPanel = new JPanel(); LabelPanel.setBackground(Color.LIGHT_GRAY); HeadPanel.setBackground(Color.LIGHT_GRAY); NumberPanel.setLayout(new GridLayout(5,4)); //LabelPanel.setLayout(new BorderLayout()); LabelPanel.setLayout(new GridLayout(1,1)); NumberPanel.add(btn1); btn1.addActionListener(this); NumberPanel.add(btn2); btn2.addActionListener(this); NumberPanel.add(btn3); btn3.addActionListener(this); NumberPanel.add(btn_add); btn_add.addActionListener(this); NumberPanel.add(btn4); btn4.addActionListener(this); NumberPanel.add(btn5); btn5.addActionListener(this); NumberPanel.add(btn6); btn6.addActionListener(this); NumberPanel.add(btn_sub); btn_sub.addActionListener(this); NumberPanel.add(btn7); btn7.addActionListener(this); NumberPanel.add(btn8); btn8.addActionListener(this); NumberPanel.add(btn9); btn9.addActionListener(this); NumberPanel.add(btn_mult); btn_mult.addActionListener(this); NumberPanel.add(btn0); btn0.addActionListener(this); NumberPanel.add(btn_dot); btn_dot.addActionListener(this); NumberPanel.add(btn_del); btn_del.addActionListener(this); NumberPanel.add(btn_div); btn_div.addActionListener(this); LabelPanel.add(txt); //LabelPanel.add(btn_equ); NumberPanel.add(btn_lpr); btn_lpr.addActionListener(this); NumberPanel.add(btn_rpr); btn_rpr.addActionListener(this); NumberPanel.add(btn_pow); btn_pow.addActionListener(this); NumberPanel.add(btn_equ); btn_equ.addActionListener(this); txt.setEditable(false); //btn_del.setEnabled(false); HeadPanel.add(new JLabel("A Java Calculator")); frame.add(LabelPanel); frame.add(NumberPanel); frame.setVisible(true); } public void actionPerformed(ActionEvent e) { if(e.getSource()==btn1) { str_number+="1"; txt.setText(str_number); } else if(e.getSource()==btn2) { str_number+="2"; txt.setText(str_number); } else if(e.getSource()==btn3) { str_number+="3"; txt.setText(str_number); } else if(e.getSource()==btn4) { str_number+="4"; txt.setText(str_number); } else if(e.getSource()==btn5) { str_number+="5"; txt.setText(str_number); } else if(e.getSource()==btn6) { str_number+="6"; txt.setText(str_number); } else if(e.getSource()==btn7) { str_number+="7"; txt.setText(str_number); } else if(e.getSource()==btn8) { str_number+="8"; txt.setText(str_number); } else if(e.getSource()==btn9) { str_number+="9"; txt.setText(str_number); } else if(e.getSource()==btn0) { str_number+="0"; txt.setText(str_number); } else if(e.getSource()==btn_lpr) { str_number+="("; txt.setText(str_number); } else if(e.getSource()==btn_rpr) { str_number+=")"; txt.setText(str_number); } else if(e.getSource()==btn_pow) { str_number+="^"; txt.setText(str_number); } else if(e.getSource()==btn_add) { str_number+="+"; txt.setText(str_number);} else if(e.getSource()==btn_sub) { str_number+="-"; txt.setText(str_number);} else if(e.getSource()==btn_mult) { str_number+="*"; txt.setText(str_number);} else if(e.getSource()==btn_div) { str_number+="/"; txt.setText(str_number);} else if(e.getSource()==btn_equ) { //System.out.println("you clicked equal sign!"); str_number+="="; txt.setText(str_number); String expression = convert(str_number); double eval = evaluate(expression); str_number+=eval; txt.setText(str_number); } else if(e.getSource()==btn_dot) { //System.out.println("you clicked dot button!"); str_number+="."; txt.setText(str_number); } else if(e.getSource()==btn_del) { //System.out.println("you clicked DEL button!"); if(str_number.length() > 0) { str_number = str_number.substring(0, str_number.length() - 1); } txt.setText(str_number); } } static String convert(String infix) { Stack as = new Stack(); String post_expression = ""; int index = 0; while(index current) { post_expression += as.pop(); } as.push(current); } index++; } while(!as.isEmpty()) { post_expression += as.pop(); } return post_expression; } static double evaluate(String postfix) { Stack as = new Stack(); char nextChar = 'm'; int index = 0; double temp = 0.00; while(index

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.