Closed how to show "no input" as error

[Penpenqt69]

Gusto ko po sana mag labas ng Error kapag wala akong na input sa 1st at 2nd pero ganito nangyayari. please help. Thank you )

 

[Impostor Syndrome]

Gawa ka lang ng input validation kung null yung mga input mo before ka mag parseInt();

if(input1 == "") {
// show error dialog box
JOPtionPane('first number required')
}
if(input2 == ""){
//show error dialog box
JOPtionPane('2nd number required')
}

disclaimer: Hindi ako java developer.

 

[Shiraori]

pwede ka din mag try catch

btn.addActionListener(new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent ae) {
        try {
            //..code mo
        }
        catch(NumberFormatException e){
            //kelangan ng import na to: import javax.swing.JOptionPane
            JOptionPane.showMessageDialog(null, "invalid input", "Error", JOptionPane.INFORMATION_MESSAGE);
        }
    }
});

 

[Penpenqt69]

Thank you mga sirs! gumagana na sya!