//set集合去重,不改变原有的顺序
public static void pastLeep1(List<String> list){
System.out.println("list = [" + list.toString() + "]");
List<String> listNew=new ArrayList<>();
Set set=new HashSet();
for (String str:list) {
if(set.add(str)){
listNew.add(str);
}
}
System.out.println("listNew = [" + listNew.toString() + "]");
}
//遍历后判断赋给另一个list集合
public static void pastLeep2(List<String> list){
System.out.println("list = [" + list.toString() + "]");
List<String> listNew=new ArrayList<>();
for (String str:list) {
if(!listNew.contains(str)){
listNew.add(str);
}
}
System.out.println("listNew = [" + listNew.toString() + "]");
}
//set去重
public static void pastLeep3(List<String> list){
System.out.println("list = [" + list + "]");
Set set = new HashSet();
List<String> listNew=new ArrayList<>();
set.addAll(list);
listNew.addAll(set);
System.out.println("listNew = [" + listNew + "]");
}
//set去重(缩减为一行)
public static void pastLeep4(List<String> list){
System.out.println("list = [" + list + "]");
List<String> listNew=new ArrayList<>(new HashSet(list));
System.out.println("listNew = [" + listNew + "]");
}
//去重并按自然顺序排序
public static void pastLeep5(List<String> list){
System.out.println("list = [" + list + "]");
List<String> listNew=new ArrayList<>(new TreeSet<String>(list));
System.out.println("listNew = [" + listNew + "]");
}
List的五种去重方式
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转载自blog.csdn.net/guanttt/article/details/80249980
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