java中String数组和List的互相转化

Posted 2021-01-25 baaigeini

转：https://www.cnblogs.com/feifeicui/p/9576864.html

1.List转String数组

方法一:

//先准备一个List
List<String> testList=new ArrayList<>();
testList.add("a");
testList.add("b");
testList.add("c");
//List转String
String[] strs1=testList.toArray(new String[testList.size()]);
for(String s:strs1){
   System.out.println(s);
}

方法二：

//先准备一个List
List<String> testList=new ArrayList<>();
testList.add("a");
testList.add("b");
testList.add("c");
//List转String
String[] strs2 = new String[testList.size()];
for(int i=0;i<testList.size();i++){
   strs2[i]=testList.get(i);
}
for(String s:strs2){
  System.out.println(s);
}

二：String数据转List

方法一：

//准备一个String数组
String[] strs = {"aa","bb","cc"};
//String数组转List
List<String> strsToList1= Arrays.asList(strs);
for(String s:strsToList1){
 System.out.println(s);
}

方法二：

//准备一个String数组
String[] strs = {"aa","bb","cc"};
//String数组转List
List<String> strsToList2=new ArrayList<>();
Collections.addAll(strsToList2,strs);
for(String s:strsToList2){
   System.out.println(s);
}

方法三：

//准备一个String数组
String[] strs = {"aa","bb","cc"};
//String数组转List
List<String> strsToList3=new ArrayList<>();
for(String s:strs){
    strsToList3.add(s);
}
for(String s:strsToList3){
    System.out.println(s);
}