if｛｝；
else｛｝；
public static void main(String[] args) { Scanner scanner = new Scanner(System.in); //从键盘接收数据 int i = 0; float f = 0.0f; System.out.println("请输入整数:"); //如果......那么 if(scanner.hasNextInt()){ i = scanner.nextInt(); System.out.println("整数数据:"+i); }else{ System.out.println("输入的不是整数数据！"); } System.out.println("请输入小数:"); if (scanner.hasNextFloat()){ f = scanner.nextFloat(); System.out.println("小数数据:"+f); }else{ System.out.println("输入的不是小数数据！"); } scanner.close(); }