if ( age == 19 && number1 == 1 && number2 == 2 )//这样
JOptionPane.showMessageDialog(null, "结果1", "输出结果", JOptionPane.INFORMATION_MESSAGE );
JOptionPane.showMessageDialog(null, "结果1", "输出结果", JOptionPane.INFORMATION_MESSAGE );
if (( age == 19 )&&( number1 == 1 )&&( number2 == 2 ))
JOptionPane.showMessageDialog(null, "结果1", "输出结果", JOptionPane.INFORMATION_MESSAGE );
else if ( number1 > 10 )
JOptionPane.showMessageDialog(null, "结果2", "输出结果", JOptionPane.INFORMATION_MESSAGE );
else if ( number2 < 20 )
JOptionPane.showMessageDialog(null, "结果3", "输出结果", JOptionPane.INFORMATION_MESSAGE );
else
JOptionPane.showMessageDialog(null, "结果4", "输出结果", JOptionPane.INFORMATION_MESSAGE );