String disp;
for(int i=0; i<31 ; i++)
disp = disp + Integer.toString(i);
JOptionPane.showMessageDialog(null, disp);
错误给出:的Java:如何在一个循环将字符串
Calendar.java:28: error: variable disp might not have been initialized JOptionPane.showMessageDialog(null, disp);
将'String disp;'更改为'String disp =“”;'或一些默认值 –