arraylist Questions

6

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I was asked the following question in an interview. How can I sort a Dictionary by the key, in the order which is in an array list. So for example I have a dictionary as follows Dictionary<s...
Clutch asked 23/4, 2014 at 21:45

35

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I wanted to create a list of options for testing purposes. At first, I did this: ArrayList<String> places = new ArrayList<String>(); places.add("Buenos Aires"); places.add("Córdoba"); ...
Meaningful asked 17/6, 2009 at 4:10

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I use a lot of lists and arrays but I have yet to come across a scenario in which the array list couldn't be used just as easily as, if not easier than, the linked list. I was hoping someone could ...
Tarango asked 26/12, 2008 at 6:52

5

I am trying to do a batch-insert of a collection of beans. One of the properties of the bean is an ArrayList. The batch update fails with the exception: Can't infer the SQL type to use for an ins...
Miranda asked 3/7, 2014 at 12:20

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I've always been one to simply use: List<String> names = new ArrayList<>(); I use the interface as the type name for portability, so that when I ask questions such as this, I can rewor...
Pestalozzi asked 27/11, 2008 at 1:36

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I've always been one to simply use: List<String> names = new ArrayList<>(); I use the interface as the type name for portability, so that when I ask questions such as this, I can rewor...
Sophistic asked 27/11, 2008 at 1:36

34

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I've always been one to simply use: List<String> names = new ArrayList<>(); I use the interface as the type name for portability, so that when I ask questions such as this, I can rewor...
Frankly asked 27/11, 2008 at 1:36

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What is the simplest way to reverse this ArrayList? ArrayList<Integer> aList = new ArrayList<>(); //Add elements to ArrayList object aList.add("1"); aList.add("2"); aList.add("3"); aL...
Gera asked 26/5, 2012 at 13:5

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I have the following qustion: How can I convert the following code snipped to Java 8 lambda style? List<String> tmpAdresses = new ArrayList<String>(); for (User user : users) { tmpAd...
Carrew asked 8/8, 2018 at 13:14

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You can set the initial size for an ArrayList by doing ArrayList<Integer> arr=new ArrayList<Integer>(10); However, you can't do arr.add(5, 10); because it causes an out of bounds ...
Minium asked 17/1, 2012 at 14:56

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I have following code which seems to be causing some memory leaks. This code snippet(i.e. hasPermissions()) get executed every time when a user performs an action. So from what I understood, since ...
Lacrimatory asked 2/10, 2023 at 1:43

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How to get the last item of an ArrayList in kotlin? I have a list like val myList = listOf("item1", "item2", "item3") I want to get the last item of myList
Navigator asked 23/10, 2018 at 11:41

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I've been tasked to do the below in a newbie Java tutorial on ArrayList // 1) Declare am ArrayList of strings // 2) Call the add method and add 10 random strings // 3) Iterate through all the el...
Uncommitted asked 8/1, 2015 at 22:44

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I have an ArrayList with custom objects that I would like to be able to save and restore on a screen rotate. I know that this can be done with onSaveInstanceState and onRestoreInstanceState if I ...
Roturier asked 19/9, 2012 at 22:34

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I'm trying to convert an ArrayList containing Integer objects to primitive int[] with the following piece of code, but it is throwing compile time error. Is it possible to convert in Java? List&lt...
Orelia asked 5/4, 2009 at 7:59

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I need to add elements to an ArrayList queue whatever, but when I call the function to add an element, I want it to add the element at the beginning of the array (so it has the lowest index) and if...
Atlas asked 18/10, 2012 at 7:52

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I have an ArrayList which is filled by Objects. My object class called Article which has two fields ; public class Article { private int codeArt; private String desArt; public Article(int aI...
Hardtack asked 31/5, 2013 at 11:46

3

I would like to know what is the difference between array (arrayOf), list (listOf), and arraylist (arrayListOf) in Kotlin? and how to use them in appropriate way? Thank you.
Lamonicalamont asked 19/4, 2023 at 5:26

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I want to remove the last object from an ArrayList quickly. I know that remove(Object O) takes O(n) in an ArrayList, but I wonder if it is possible to do this in constant time since I just want to...
Gavette asked 7/6, 2013 at 15:27

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In Java, ArrayList and HashMap are used as collections. But I couldn't understand in which situations we should use ArrayList and which times to use HashMap. What is the major difference between bo...
Sumatra asked 7/3, 2010 at 9:46

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There is probably a simple one-liner that I am just not finding here, but this is my question: How do I check if an ArrayList contains all of the objects in another ArrayList? I am looking (if it ...
Fraenum asked 24/1, 2013 at 22:5

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is there any way to check if a collection contain a value or more with better performance than looping twice with contains? in other meaning something that would look like this person.contains("...
Aldehyde asked 24/12, 2013 at 5:38

6

I am trying to sort an ArrayList of Strings that represent card values. So, some cards contain letters ("King") and some contain Strings containing only a number ("7"). I know to use Collections.so...
Derisible asked 8/6, 2010 at 16:9

5

I made a Stack and an ArrayList to make a research. Actually I want now to make my Stack replaced by an ArrayList, but how to transform a Stack into an ArrayList ? How is it going with push, pop .....
Nashua asked 4/2, 2015 at 5:9

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I tried to create a list of maps. In the following code, I'm expecting to get [{start=1,text=ye}, {start=2,text=no}] however, I only got [{start=2,text=no}, {start=2,text=no}] How to avoid o...
Birt asked 4/11, 2010 at 19:29

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