我想用java

Question

這是方程 （輸入/ 750）* 6 這裏，任何值i作爲輸入輸入，它將由750分，然後通過6 此相乘是的樣品，使該計算我寫的代碼

JButton btnCalculate = new JButton("Calculate"); 
     btnCalculate.addActionListener(new ActionListener() { 
      public void actionPerformed(ActionEvent e) { 
       try{ 
        String r=textFieldInput.getText(); 
        int u=Integer.parseInt("750"); 
        String z1 = r/u *6; /*on this line, i'm getting this error "The operator/is undefined for the argument type(s) String, int" */ 

        textField.setText(z1); 

       }catch(Exception ei) { 
        JOptionPane.showMessageDialog(null, "Invalid Input: Please Enter Number"); 
} 

請問我該從哪裏出發？

Answer 1

JButton btnCalculate = new JButton("Calculate"); 
btnCalculate.addActionListener(new ActionListener() { 
    public void actionPerformed(ActionEvent e) { 
     try{ 
       textField.setText(String.valueOf(Double.parseDouble(textFieldInput.getText())*0.008)); 
      }catch(Exception ei) { 
       JOptionPane.showMessageDialog(null, "Invalid Input: Please Enter Number"); 
}