arraylist

问题 I want to make turn this program's array into an ArrayList. So far I know that the array will turn into ArrayList<StudentList> list = new ArrayList<StudentList>(); and that each list[i] will turn into: list.get(i) however I am not sure what the following line will be in order to satisfy the ArrayList version list[i] = new StudentList(); so here is the full code: public static void main(String[] args) { StudentList[] list = new StudentList[5]; int i; for (i = 0; i < list.length; ++i) { list[i]

问题 I created a user defined data type and read data from a file. Here are the codes: Student Class: package system.data; public class Student { private String firstName; private String lastName; private String regNumber; private int coursework1Marks; private int coursework2Marks; private int finalExamMarks; private double totalMarks; public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return

问题 This question already has answers here : Optimize this ArrayList join method (9 answers) Closed 2 years ago . I am currently trying to append a semi-colon onto the end of each element in an ArrayList . The code: ArrayList<String> emailAddresses = new ArrayList<String>(); public void getEmailAddresses() throws InterruptedException { driver.findElement(By.className("userlink-0")).click(); String emailAddress = driver.findElement(By.id("email")).getText(); emailAddresses.add(emailAddress); hs

问题 I've made my own custom ArrayList like this: public class Points { String hoodName; Double points; Integer hoodId; public Points(String hN, Double p, Integer hI){ hoodName = hN; points =p; hoodId = hI; } public Double getPoints() { return points; } public Integer getHoodId() { return hoodId; } public String getHoodName() { return hoodName; } } When I'm adding data from my JSON api it adds item multiple times. I've tried this code to add the items only once it: if (!points.contains(jsonObject

问题 I am trying to populate an ArrayList over multiple table columns, this was originally done using Scriptlets on our old page but I know that the practice is frowned upon now. And I am having trouble translating it over using struts tags. I want the table to end up like this, Checkbox 1 Name 1 Checkbox 2 Name 2 Checkbox 3 Name 3 Checkbox 4 Name 4 etc.... This is the original scriptlet code: <% for (int j=0; j < getDocumentList().length; j++) { setPacket(j); setStringIndex(Integer.toString(j));

问题 I need to sort a shopping list by the aisle the item is located for example: [Bread] [1] [Milk] [2] [Cereal] [3] I am planning to do this with ArrayList and was wondering how to make an 2D ArrayList Bonus questions: any ideas on how to sort by the aisle number? 回答1: Don't you have a class that holds your item + aisle information? Something like: public class Item { private String name; private int aisle; // constructor + getters + setters } If you don't, consider making one - it's definitely

问题 The object in the arraylist is defined in an external library. The object contains some int values and also a float[]. How can I pass all the ArrayList from an activity to another? Thanks! By the way, I do not have the control of the object class. 回答1: It depends on the type of object that's in the array list. If you have control over it and can have it implement Parcelable, then you can use Intent.putParcelableArrayListExtra . Another approach is to extend Application and store your

问题 I have a problem with fast read txt file to ArrayList. If I want read a file size 0,9MB, I must wait 5min. If files size is 34MB (partialy, because android does not accept larger than 1MB files), it's completely not working. I think that process should be max few second. This is a code: String word; public ArrayList<String> dictionary = new ArrayList<String>(); public void setup() { try { AssetManager assetManager = getAssets(); InputStream inputf; inputf = assetManager.open("dict_1.txt");

问题 I'm trying to sort an ArrayList of String . Given: {A,C,AA,B,CC,BB} Arraylist.Sort gives: {A,AA,B,BB,C,CC} What I need is: {A,B,C,AA,BB,CC} 回答1: This is kind of old school but, I went the IComparer Interface . . . public class SortAlphabetLength : System.Collections.IComparer { public int Compare(Object x, Object y) { if (x.ToString().Length == y.ToString().Length) return string.Compare(x.ToString(), y.ToString()); else if (x.ToString().Length > y.ToString().Length) return 1; else return -1;