AWT based Java program to implement basic calculator
Calculator Program in Java:
import java.awt.*; import java.awt.event.*; class Calculator extends Frame implements ActionListener { TextField tfInput; Panel panel; String btnString[] = {"7", "8", "9", "+", "4", "5", "6", "-", "1", "2", "3", "*", "C", "0", "=", "/"}; Button btn[] = new Button[16]; int num1 = 0, num2 = 0, result = 0; char op; public Calculator() { Font f = new Font("Cambria", Font.BOLD, 18); tfInput = new TextField(10); tfInput.setFont(f); panel = new Panel(); add(tfInput, "North"); add(panel, "Center"); panel.setLayout(new GridLayout(4,4)); for(int i=0; i < 16; i++) { btn[i] = new Button(btnString[i]); btn[i].setFont(f); btn[i].addActionListener(this); panel.add(btn[i]); } addWindowListener(new WindowAdapter(){ public void windowClosing(WindowEvent we) { System.exit(0); } }); } public void actionPerformed(ActionEvent ae) { String str = ae.getActionCommand(); if(str.equals("+")) { op = '+'; num1 = Integer.parseInt(tfInput.getText()); tfInput.setText(""); } else if(str.equals("-")) { op = '-'; num1 = Integer.parseInt(tfInput.getText()); tfInput.setText(""); } else if(str.equals("*")) { op = '*'; num1 = Integer.parseInt(tfInput.getText()); tfInput.setText(""); } else if(str.equals("/")) { op = '/'; num1 = Integer.parseInt(tfInput.getText()); tfInput.setText(""); } else if(str.equals("=")) { num2 = Integer.parseInt(tfInput.getText()); switch(op) { case '+' : result = num1 + num2; break; case '-' : result = num1 - num2; break; case '*' : result = num1 * num2; break; case '/' : result = num1 / num2; break; } tfInput.setText(result + ""); result = 0; } else if(str.equals("C")) { tfInput.setText(""); num1 = num2 = result = 0; } else { tfInput.setText(tfInput.getText() + str); } } public static void main(String args[]) { Calculator c1 = new Calculator(); c1.setTitle("Calculator"); c1.setSize(250,300); c1.setVisible(true); } }
Output: