arraylist

问题 It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 7 years ago . I need to create a list array in java that can hold three different objects (Surname, forename, Result) and was wondering how to do that 回答1: The best and also Object Oriented approach is to Create a class with

问题 My objective is to create a map. It have reqid , name and lowest status number of a set as a key. Here set refers to rows belonging to a specific Reqid . The value of the map is an Arraylist which consists of all rows as objects of a specific id . public class MapKey { private Integer id; private String name; private Integer status; public MapKey(Integer id, String name,Integer status) { this.id = id; this.name = name; this.status=status; } @Override toString,hashCode,equals public class

问题 My objective is to create a map. It have reqid , name and lowest status number of a set as a key. Here set refers to rows belonging to a specific Reqid . The value of the map is an Arraylist which consists of all rows as objects of a specific id . public class MapKey { private Integer id; private String name; private Integer status; public MapKey(Integer id, String name,Integer status) { this.id = id; this.name = name; this.status=status; } @Override toString,hashCode,equals public class

问题 This question already has answers here : Why does my ArrayList contain N copies of the last item added to the list? (5 answers) Closed 12 days ago . Hy, I'm a bit new to JAVA, and having a big problem. While I'm adding elements to a List<int[]> the result will be a List full of with the same value. Why JAVA is working like this? Here is the code: // Global variables private static int rows = 20; private static int columns = 30; private static String[][] labirinth = new String[rows][columns];

问题 This question already has answers here : Why does my ArrayList contain N copies of the last item added to the list? (5 answers) Closed 12 days ago . Hy, I'm a bit new to JAVA, and having a big problem. While I'm adding elements to a List<int[]> the result will be a List full of with the same value. Why JAVA is working like this? Here is the code: // Global variables private static int rows = 20; private static int columns = 30; private static String[][] labirinth = new String[rows][columns];

问题 So I got this code so far: int secondLargest = list.get(0); int largest = list.get(0); for (int i = 0; i < list.size(); i++) { if(list.get(i) > largest) { secondLargest = largest; largest = list.get(i); if(list.get(i) > secondLargest && list.get(i) != largest) { secondLargest = list.get(i); } } } System.out.print("Second biggest number "); return secondLargest; The problem is that when I use this code (the list is:) list2.add(1); list2.add(2); list2.add(10); list2.add(9); list2.add(8); list2

问题 I have an ArrayList of String arrays which is added to like so: List<String[]> data = new ArrayList<>(); data.add(new String[] {var, lex, valor}); When trying to erase one of the String arrays the output is false for some reason. Here's how I remove it: data.remove(new String[] {var, lex, valor}); I've also tried removing using position, the method is as follows: public void eliminarPos(String var, String lex, String valor, Integer ii) { boolean uno = data.remove(ii); System.out.println(uno);

问题 I have an ArrayList of String arrays which is added to like so: List<String[]> data = new ArrayList<>(); data.add(new String[] {var, lex, valor}); When trying to erase one of the String arrays the output is false for some reason. Here's how I remove it: data.remove(new String[] {var, lex, valor}); I've also tried removing using position, the method is as follows: public void eliminarPos(String var, String lex, String valor, Integer ii) { boolean uno = data.remove(ii); System.out.println(uno);

问题 I have a data class like this data class Person(val id: Long = BaseDataContract.BaseData.UNDEFINED_ID.toLong(), ..... val personConsents: ArrayList<PersonConsent> = ArrayList<PersonConsent>()) I have two copies of the object: person = originalPerson.copy() Then I change the elements of personConsents for the object person - I add/delete/edit them. But by some reason I see that the same changes are happening in originalPerson object which I don't want to be. originalPerson is not supposed to

问题 I have 2 Lists: // old list List<Employee> oldList = new ArrayList<>(); Employee emp1 = new Employee(); emp1.setPersonalNumber("123"); emp1.setName("old_name1"); emp1.setStatus(Status.OLD); Employee emp2 = new Employee(); emp2.setPersonalNumber("456"); emp2.setName("old_name2"); emp2.setStatus(Status.OLD); oldList.add(emp1); oldList.add(emp2); // new list List<Employee> newList = new ArrayList<>(); Employee newEmp1 = new Employee(); newEmp1.setPersonalNumber("123"); newEmp1.setName("new_name1