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Calculator Problem. Thanks for helping! ^^
greetings programmers. . can u help me with this project of mine?
it needs a pemdas and mdas rule . but i dont know how to put it.
can u please help me with this?
i really appreciate ur help. thanks guys. .
God bless
import javax.swing.*;
import java.awt.event.*;
import java.awt.*;
import java.util.*;
public class MDAS {
private String inputString = null;
JLabel expression = new JLabel("Expression: ");
JLabel result = new JLabel("Result: ");
JTextField expression_textf = new JTextField(20);
JTextField result_textf = new JTextField(10);
JButton calculate = new JButton(" Calculate");
JButton clear = new JButton(" Clear ");
JButton cancel = new JButton (" Cancel ");
//text functions
public JPanel text_2() {
JPanel Panel1 = new JPanel();
JPanel Panel2 = new JPanel();
Panel1.setLayout(new GridLayout(4,4));
Panel1.add(expression);
Panel1.add(expression_textf);
Panel1.add(result);
Panel1.add(result_textf);
result_textf.setEnabled(false);
result_textf.setFont(new Font("Comic Sans Ms", Font.PLAIN, 18));
Panel2.setLayout(new FlowLayout(FlowLayout.RIGHT));
Panel2.add(Panel1);
return Panel2;
}
//Button functions
public JPanel buttons_3(){
clear.addActionListener ( new ActionListener () {
public void actionPerformed (ActionEvent e) {
clear();
}
});
calculate.addActionListener ( new ActionListener () {
public void actionPerformed (ActionEvent e) {
process();
}
});
cancel.addActionListener ( new ActionListener () {
public void actionPerformed (ActionEvent e) {
process();
}
});
JPanel Panel1 = new JPanel();
JPanel Panel2 = new JPanel();
Panel1.setLayout(new GridLayout(5, 6));
Panel2.add(calculate);
Panel2.add(clear);
Panel2.add(cancel);
Panel2.setLayout(new FlowLayout(FlowLayout.RIGHT));
Panel2.add(Panel1);
return Panel2;
}
//Processing and display output
protected void process()
{
// get the input string
inputString = expression_textf.getText();
// Out the string
inputString = inputString.trim();
// Ensure there are characters to process
if (inputString.length() > 0)
// check syntax, evaluate and display results if correct
if ( checkSyntax() )
result_textf.setText( ""+ evaluate() );
}
protected boolean checkSyntax()
{
int opCount = 1; // Start with a value
boolean hasDec = false; // Does the current # have a decimal component?
int i;
// Check each character
for (i = 0; i < inputString.length(); i++)
switch(inputString.charAt(i))
{
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
opCount = 0;
break;
case '.':
if (((opCount += 2) > 2) || hasDec)
hasDec = true;
break;
case '%':
case '/':
case '*':
if (opCount++ > 0)
hasDec = false;
break;
case '%':
case '+':
case '-':
if (opCount++ > 1)
hasDec = false;
break;
default:
return reportError(i);
}
// Make sure expression ends with a value
return true;
}
protected double evaluate()
{
// Temp token handle
String tok1, tok2;
// Create a string tokenizer object, keeping the delimiters as tokens
StringTokenizer tokens = new StringTokenizer( inputString, "+-/*", true );
// get the first token and put its value into result
if ((tok1 = tokens.nextToken()).equals("*"))
tok1 = tokens.nextToken();
else if (tok1.equals("/"))
tok1 = "-".concat(tokens.nextToken());
else if (tok1.equals("+"))
tok1 = "-".concat(tokens.nextToken());
else if (tok1.equals("-"))
tok1 = "-".concat(tokens.nextToken());
else if (tok1.equals("%"))
tok1 = "%".concat(tokens.nextToken());
double result = new Double(tok1).doubleValue();
// Evaluate the expression
while (tokens.hasMoreTokens())
{
// Get the operator token
tok1 = tokens.nextToken();
// Get the second operand token
if ((tok2 = tokens.nextToken()).equals("*"))
tok2 = tokens.nextToken();
else if (tok2.equals("/"))
tok2 = "-".concat(tokens.nextToken());
else if (tok2.equals("+"))
tok2 = "-".concat(tokens.nextToken());
else if (tok2.equals("-"))
tok2 = "-".concat(tokens.nextToken());
else if (tok2.equals("%"))
tok2 = "%".concat(tokens.nextToken());
// Evaluate the subexpression
switch (tok1.charAt(0))
{
case '+':
result += new Double(tok2).doubleValue();
break;
case '-':
result -= new Double(tok2).doubleValue();
break;
case '/':
result /= new Double(tok2).doubleValue();
break;
case '*':
result *= new Double(tok2).doubleValue();
break;
case '%':
result %= new Double(tok2).doubleValue();
break;
}
}
return result;
}
public void clear() {
expression_textf.setText("");
result_textf.setText("");
}
protected boolean reportError( int index )
{
// create a new string with the first line of output
String outputString = new String("Invalid Number\n");
// copy the output string text to the output text area
result_textf.setText( outputString );
return false;
}
public JFrame buildNewFrame() {
try{
UIManager.setLookAndFeel(
UIManager.getSystemLookAndFeelClassName());
}catch(Exception e){}
MDAS re = new MDAS();
JPanel nPanel = new JPanel();
JPanel sPanel = new JPanel();
JPanel fPanel = new JPanel();
nPanel = re.text_2 ();
sPanel = re.buttons_3 ();
fPanel.setLayout( new BorderLayout());
fPanel.add(nPanel, BorderLayout.CENTER);
fPanel.add(sPanel, BorderLayout.SOUTH);
JFrame frame = new JFrame("MDAS");
frame.setSize(50,50);
frame.getContentPane().add(fPanel);
frame.addWindowListener( new WindowAdapter() {
public void windowClosing( WindowEvent e) {
System.exit(0);
}
});
return frame;
}
}
/// runner ///
import javax.swing.JFrame;
public class MDAS_Runner {
public static void main(String args[]){
JFrame run = new JFrame();
MDAS rece = new MDAS ();
run = rece.buildNewFrame();
run.pack();
run.setVisible(true);
}
}
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Linear Mode
