age1和age2的差值？应该用绝对值更严谨把？如何使用绝对值呢

public class HelloWorld{
    public static void main(String[] args) {
  int age1=24;
  int age2=18;
  int age3=36;
  int age4=27;
  int sum = age1 + age2 + age3 + age4;
     float avg = sum / 4;
  int minus = age1 - age2;//最好是z
  int newAge = --age1;
  
     System.out.println("年龄总和："+sum);
     System.out.println("平均年龄："+avg);
  System.out.println("年龄差值："+minus);
  System.out.println("自减后的年龄："+newAge);

 }
}