在java項(xiàng)目中怎么對(duì)數(shù)組進(jìn)行合并

//方法一 Arrays類
  String[] a = {"A","B","C"};
  String[] b = {"D","E"};
  // List<String> list = Arrays.asList(a);  --OK
  // List<String> list = Arrays.asList("A","B","C"); --OK
  // list.add("F"); --UnsupportedOperationException
  // list.remove("A"); --UnsupportedOperationException
  // list.set(1,"javaee");--OK (因?yàn)槭前褦?shù)組轉(zhuǎn)為集合，其本質(zhì)還是數(shù)組，數(shù)組長度固定不變，但內(nèi)容可以改變)
  // 結(jié)論：雖然可以把數(shù)組轉(zhuǎn)為集合，但是集合長度不能改變

  List list = new ArrayList(Arrays.asList(a));
  list.addAll(Arrays.asList(b));
  String[] str = new String[list.size()];
  list.toArray(str);  
  for(int x=0;x<str.length;x++){
    System.out.print(str[x] + " ");
  }
//方法二 循環(huán)遍歷
// 兩個(gè)數(shù)組合并
  String[] str1 = {"Hello","world","java"};
  String[] str2 = {"Veriable","syntax","interator"};
  String[] newStr = new String[str1.length+str2.length];
  //newStr = str1;數(shù)組是引用類型
  for(int x=0;x<str1.length;x++){
    newStr[x] = str1[x];
  }    
  for(int y=0;y<str2.length;y++){
    newStr[str1.length+y]=str2[y];
  }
  for(int y=0;y<newStr.length;y++){
    System.out.println(newStr[y] + " ");
  }
// 方法三
  String[] str1 = {"Hello","world","java"};
  String[] str2 = {"Veriable","syntax","interator"};
  int str1Length = str1.length;
  int str2length = str2.length;
    
  str1 = Arrays.copyOf(str1, str1Length+str2length);//數(shù)組擴(kuò)容
  System.arraycopy(str2, 0, str1, str1Length, str2length);
  System.out.println(Arrays.toString(str1));