user interface - JAVA : parse int method while using it in JTextField not working -

user interface - JAVA : parse int method while using it in JTextField not working -

i made simple code calculate bmi shows error in line parseint method can help (a bit new java :p)

public bmif(){ super("bmi calculator"); setlayout(new flowlayout()); t1 = new jtextfield("enter wieght in kg",10); final int num1 =integer.parseint(t1.gettext()); add(t1); t2 = new jtextfield("enter hieght in m",10); final int num2 =integer.parseint(t2.gettext()); add(t2); t3 = new jtextfield("",10); t3.seteditable(false); add(t3, borderlayout.south); b = new jbutton("claculate bmi"); add(b); b.addactionlistener( new actionlistener(){ public void actionperformed(actionevent event) { int k = num1/(num2*num2); t3.settext(string.format("your bmi %d",k)); } } ); }

}

you're trying parse string "enter weight in kg" int. see java doc here initialization means.

you need parse string in actionlistener , add together catch exception rule.

i've gotten bellow code work. problem have need declare int or double in try block of code without final qualifier, can alter variable after initialization

frame.setlayout(new flowlayout()); textarea.seteditable(true); textarea.setpreferredsize(new dimension(50, 15)); button = new jbutton("ok"); button.addactionlistener(new actionlistener() { @override public void actionperformed(actionevent e) { seek { string string = textarea.gettext().trim(); int weight = integer.parseint(string); //do stuff weight variable system.out.println(weight); } catch(exception e1) { system.out.println("number exception"); } } }); frame.add(textfield); frame.add(textarea); frame.add(button); frame.setsize(300, 100); frame.setvisible(true); frame.setdefaultcloseoperation(jframe.exit_on_close);

user-interface jtextfield parseint