1，計算陣列的最大值
2，計算陣列的最小值
3，計算陣列和
4，合併陣列
5，擷取陣列

 public class ArrayEvent{

 //1，計算陣列中的最大值
 public static int arrMax(int[] arr1){
  if(arr1 == null){
  //IllegalArgumentException 引數異常
  //如果arr1 == null時，發生異常，提示"arr1 must be not null.
            throw new IllegalArgumentException("arr1 must be not null."
 
);   
  }
  int max = Integer.MIN_VALUE;//將max先定為最小值
  for(int i = 0;i < arr1.length;i++){
   if(arr1[i] > max){
    max = arr1[i];
   }
  }
  return max;
 }


 //2，計算陣列中的最小值
 public static int arrMin(int[] arr1){
  if(arr1 == null){
            throw new IllegalArgumentException("arr1 must be not null."
 
);
  }
  int min = Integer.MAX_VALUE;
  for(int i = 0;i < arr1.length;i++){
   if(arr1[i] < min){
    min = arr1[i];
   }
  }
  return min;
 }


 //3，計算陣列值之和
 public static int arrSum(int[] arr1){
  if(arr1 == null){
            throw new IllegalArgumentException("arr1 must be not null.");
  }
  int
 
 sum = 0;
  for(int i = 0;i < arr1.length;i++){
   sum = sum + arr1[i];
  }
  return sum;
 }


 //4，陣列拼接
 public static int[] arrJoin(int[] arr1,int[] arr2){
  if(arr1 == null){
            throw new IllegalArgumentException("arr1 must be not null.");
  }
  if(arr2 == null){
            throw new IllegalArgumentException("arr2 must be not null.");
  }
  int arr3[] = new int[arr1.length+arr2.length];
  for(int i = 0;i < arr1.length;i++){
   arr3[i] = arr1[i];
  }
  for(int i = arr1.length;i < arr3.length;i++){
   arr3[i] = arr2[i - arr1.length];
  }
  return arr3;
 }


 //5，陣列擷取
 public static int[] arrCut(int[] arr1,int start,int end){
  if(arr1 == null){
            throw new IllegalArgumentException("arr1 must be not null.");
  }
  if(start < 0 || end < 0){
   throw new IllegalArgumentException("start or end must be not < 0");
  }
  if(end < start){
   throw new IllegalArgumentException("end must be not < start");
  }
  if(start >= arr1.length){
   throw new IllegalArgumentException("start must be < arr1.length");
  }
  if(end >= arr1.length){
   throw new IllegalArgumentException("end must be < arr1.length");
  }
  //是否end也不能大於等於arr1.length
  int count = end - start;
  int[] arr3 = new int[count];
  for(int i = 0; i < count;i++){
   arr3[i] = arr1[start+i];
  }
  return arr3;
 }
 public static void printArray(int[] arr){
  for(int i = 0;i < arr.length;i++){
   System.out.print(arr[i]+"\t");
  }
  System.out.println();
 }
 public static void main(String[] args){
  int[] arr1 = new int[]{11,2,45,67,8,90};
  int[] arr2 = new int[]{1,2,3};
  System.out.println(arrMax(arr1));
  System.out.println(arrMin(arr1));
  System.out.println(arrSum(arr1));
  int[] join = arrJoin(arr1,arr2);
  printArray(join);
  int[] cut = arrCut(arr1,0,6);
  printArray(cut);
 }
}