How to write code in Java to compare sizes?

In Java, comparison operators (<, >, <=, >=, ==, !=) can be used to compare sizes.

Here is an example code comparing the sizes of two integers:

public class CompareNumbers {
    public static void main(String[] args) {
        int num1 = 10;
        int num2 = 20;

        if (num1 > num2) {
            System.out.println(num1 + " 大于 " + num2);
        } else if (num1 < num2) {
            System.out.println(num1 + " 小于 " + num2);
        } else {
            System.out.println(num1 + " 等于 " + num2);
        }
    }
}

Running the above code will output: 10 is less than 20, because the first number is smaller than the second number.

You can also encapsulate the above code into a method for reuse. For example:

public class CompareNumbers {
    public static void compare(int num1, int num2) {
        if (num1 > num2) {
            System.out.println(num1 + " 大于 " + num2);
        } else if (num1 < num2) {
            System.out.println(num1 + " 小于 " + num2);
        } else {
            System.out.println(num1 + " 等于 " + num2);
        }
    }

    public static void main(String[] args) {
        int num1 = 10;
        int num2 = 20;
        compare(num1, num2);
    }
}

In this way, you only need to call the compare() method and pass in two integers that need to be compared.