JAVA - Ignoring '$' in getText

Question

I am running into issues with my school assignment, where we have to create a PoS for a fast food company. Part of the assignment is calculating change after typing in the amount tendered. The problem I am having is the program cannot subtract the grand total from the amount tendered due to '$'. My code currently looks like this:

    private void totalButtonActionPerformed(java.awt.event.ActionEvent evt) {                                            
          
    // Finding the subtotal
            double burgers;
            double fries;
            double drinks;
            double subtotal;
            
            burgers = 2.49;
            fries = 1.89;
            drinks = 0.99;
            
            subtotal = Double.parseDouble (burgerInput.getText ()) * burgers 
                    + Double.parseDouble (fryInput.getText ()) * fries 
                    + Double.parseDouble (drinkInput.getText ()) * drinks;
           
            
            DecimalFormat w = new DecimalFormat("###,###0.00");
            subtotalOutput.setText("$" + w.format(subtotal));
            
    // Calculating Tax
            double taxpercentage;
            double tax;
            
            taxpercentage = 0.13;
            
            tax = subtotal * taxpercentage;
            
            DecimalFormat x = new DecimalFormat("###,###0.00");
            taxesOutput.setText("$" + x.format(tax));
    
    // Grand Total
            double grandtotal;
            
            grandtotal = subtotal + tax;
            
            DecimalFormat y = new DecimalFormat("###,###0.00");
            grandtotalOutput.setText("$" + y.format(grandtotal));
            
    
                                                  

and for calculating change:

// Calculating Change
        double tendered;
        double grandtotal;
        double change;
        
        tendered = Double.parseDouble(tenderedInput.getText ());
        grandtotal = Double.parseDouble(grandtotalOutput.getText ());
        change = tendered - grandtotal;
        
        DecimalFormat z = new DecimalFormat("###,###0.00");
        changeOutput.setText("$" + z.format(change));
                                             

How can I keep the '$' in the grandtotalOutput box but still be able to calculate the change properly?

Answer 1

The $ and comma need to be removed from the text in order for it to be parsed into a double number. You can do so by chaining String#replace, first to replace , with a blank text and then $ with a blank text.

tendered = Double.parseDouble(tenderedInput.getText().replace(",", "").replace("$", ""));
grandtotal = Double.parseDouble(grandtotalOutput.getText().replace(",", "").replace("$", ""));

Note: The replacements can be done in any order (i.e. first replace $ with a blank text and then , with a blank text).