Java给出错误：无法比较的类型：boolean和int“即使两个方法都是布尔值？

What Im trying to code is that a user inputs a number n and the program outputs all the numbers from 1 to n that are both prime numbers and palindrome numbers. I created a method for finding prime numbers and another for finding if a number is a palindrome. My code for outputting the integers that are both goes like

我试图编码的是用户输入数字n,程序输出从1到n的所有数字,它们都是素数和回文数。我创建了一种查找素数的方法,另一种用于查找数字是否为回文数据。我输出整数的代码都是这样的

if ((prime(y)==true) && (pal(y)==n)) {
            System.out.println(y);
        }

Here is my method for finding prime numbers:

这是我查找素数的方法:

public static boolean prime(int n) {
    int x = 2;
    while (n%x>0) {
        x+=1;
    } if (x==n) {
        return true;
    } else {
        return false;
    }
}

Here's my method for finding palindrome numbers:

这是我查找回文数的方法:

public static boolean pal(int n) {
    int rev = 0;
    int rmd = 0;
    while (n>0) {
        rmd = n%10;
        rev = rev*10 + rmd;
        n = n/10;
    } if (rev==n) {
        return true;
    } else {
        return false;
    }
}

I get the error that these two methods are not comparable because apparently one is boolean and the other integer. Anyone know how to fix this?

我得到这两个方法无法比较的错误,因为显然一个是布尔值而另一个是整数。有人知道怎么修这个东西吗?

1 个解决方案

#1

Your statement says pal(y)==n, but pal(y) returns a boolean. I'm not sure what comparing it to n is supposed to do.

你的陈述说pal(y)== n,但是pal(y)返回一个布尔值。我不确定将它与n进行比较应该做什么。

In general, avoid statements like foo == true. If it's already a boolean, just use foo, or for false !foo.

通常,避免使用foo == true之类的语句。如果它已经是布尔值,只需使用foo,或者使用false!foo。

#1