public class MergeOrderedArray {  public static int[] merge(int [] a,int []b){   if(!isOrderedArray(a)){    System.out.println(" array a is not an ordered array.");    return null;   }       if(!isOrderedArray(b)){    System.out.println(" array b is not an ordered array.");    return null;   }      int a_len = a.length;   int b_len = b.length;   int[] merge = new int[a_len+b_len];   int i=0,j=0,k=0;   while(i<a_len&&j<b_len){    if(a[i]<b[j]){     merge[k++]=a[i++];    }else{     merge[k++]=b[j++];    }   }      //A數組全部合并完畢，將b數組剩余直接加入合并數組   if(i==a_len){    for(;j<b_len;j++){     merge[k++]= b[j];    }   }else{    for(;i<a_len;i++){     merge[k++]= a[i];    }   }      return merge;     }   public static boolean isOrderedArray(int [] array){   if(array==null||array.length==0){    return false;   }      for(int i = 0;i<array.length-1;i++){    if(array[i]>array[i+1]){     return false;    }   }   return true;  }    public static void main(String[] args) {   int a [] = {1,2,3,4,5};   int b [] = {2,3,4,5,6,7,8,9};   int [] merge = merge(a,b);   System.out.println(Arrays.toString(merge));  } }