好久沒寫了，論壇看到了，寫一下

int[] array = {1,8,6,3,8,45,62,21,100,98};
		for(int i = 0;i<array.length;i++){
			int a = array[i];
			int k=i;
			for(int j=i+1;j<array.length;j++){
				if(array[i]<array[j]){
//					int temp =array[i];
//					array[i] =array[j];
//					array[j] = temp;兩種不同的調換順序
					array[i] +=array[j];
					array[j] =array[i]-array[j];
					array[i] = array[i]-array[j];
				}
			}
		}
		for(int i = 0;i<array.length;i++){
			System.out.print(array[i]+",");
		}
 

 字串倒敘輸出

String str="abc減肥減肥";
StringBuffer stringBuffer = new StringBuffer (str);
    System.out.print(stringBuffer.reverse());