Java Add elements to arraylist with FOR loop where element name has increasing number

Question

I have an arraylist where I want to add elements via a for loop   Answer answer1  Answer answer2  Answer answer3   ArrayList lt Answer gt  answers   new ArrayList 3    for  int i 0 i lt 3 i          answers add   HOWTO  Add each of the answers        EDIT  How would this go if I have  let s say 50 Answer elements

User · Accepted Answer

You can t do it the way you re trying to    can you perhaps do something like this   List lt Answer gt  answers   new ArrayList lt Answer gt     for int i 0  i  lt  4  i       Answer temp   new Answer        do whatever initialization you need here   answers add temp

User · Answer

Put the answers into an array and iterate over it   List lt Answer gt  answers   new ArrayList lt Answer gt  3    for  Answer answer   new Answer    answer1  answer2  answer3         list add answer       EDIT  See Jo  o s answer for a much better solution  I m still leaving my answer here as another option

User · Answer

There s always some reflection hacks that you can adapt  Here is some example  but using a collection would be the solution to your problem  the integers you stick on your variables name is a good hint telling us you should use a collection     public class TheClass        private int theField  42       public static void main String   args  throws Exception            TheClass c  new TheClass             System out println c getClass   getDeclaredField  theField   get c

User · Answer

Thomas s solution is good enough for this matter   If you want to use loop to access these three Answers  you first need to put there three into an array-like data structure ---- kind of like a principle  So loop is used for operating on an array-like data structure  not just simply to simplify typing task  And you cannot use FOR loop by simply just giving increasing-number-names to the elements

User · Answer

That can t be done with a for-loop  unless you use the Reflection API  However  you can use Arrays asList instead to accomplish the same   List lt Answer gt  answers   Arrays asList answer1  answer2  answer3

User · Answer

I assume Answer as an Integer data type so in this case  you can easily use Scanner class for adding the multiple elements say 50   private static final Scanner obj   new Scanner System in   private static ArrayList lt Integer gt  arrayList   new ArrayList lt Integer gt  50   public static void main String   S   for  int i 0 i lt 50 i          Using Scanner class object to take input      arrayList add obj nextInt          You can also check the elements of your ArrayList    for  int i 0 i lt 50 i         Using get function for fetching the value present at index  i      System out print arrayList get i   quot   quot        This is a simple and easy method for adding multiple values in an ArrayList using for loop  As in the above code  I presume the Answer as Integer it could be String  Double  Long et Cetra  So  in that case  you can use next    nextDouble    and nextLong   respectively

User · Answer

Using Random function to generate number and iterating them on al using for loop  ArrayList lt Integer gt  al new ArrayList lt Integer gt  5       for  int i 0 i lt  4 i             Random rand new Random            al add i rand nextInt 100            System out println al         System out println al size

User · Answer

why you need a for-loop for this  the solution is very obvious   answers add answer1   answers add answer2   answers add answer3     that s it  no for-loop needed

User · Answer

If you simply need a list  you could use   List lt Answer gt  answers   Arrays asList answer1  answer2  answer3     If you specifically require an ArrayList  you could use   ArrayList lt Answer gt  answers   new ArrayList Arrays asList answer1  answer2  answer3

[java] Java: Add elements to arraylist with FOR loop where element name has increasing number

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