?int age1=24;
??int age2=18;
??int age3=36;
??int age4=27;
??int sum=age1+age2+age3+age4;
??????? double avg=sum/4;
??????? int minus=age1-age2;
??????? int newAge=--age1;
???? System.out.println("年齡總和："+sum);
??? ?System.out.println("平均年齡："+avg);
??System.out.println("年齡差值："+minus);
??System.out.println("自減后的年齡："+newAge);