关于scanner.hasNextFloat() 的问题?

public class Demo04 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.println("请输入小数:");
        float f = 0.0f;
        if(scanner.hasNextFloat()){
            f = scanner.nextFloat(); // 2
            System.out.println("小数为:"+f); // 2.0
        } else {
            System.out.println("你输入的数不是小数啊");
        }
    }
}