Try something like List<String> myList = new ArrayList<String>(Arrays.asList(s.split(“,”))); Arrays.asList documentation String.split documentation ArrayList(Collection) constructor documentation Demo: String s = “lorem,ipsum,dolor,sit,amet”; List<String> myList = new ArrayList<String>(Arrays.asList(s.split(“,”))); System.out.println(myList); // prints [lorem, ipsum, dolor, sit, amet] This post has been rewritten as an article here.
You can do the following: String [] strings = new String [] {“1”, “2” }; List<String> stringList = new ArrayList<String>(Arrays.asList(strings)); //new ArrayList is only needed if you absolutely need an ArrayList
Since I couldn’t find a similar flowchart I decided to make one myself. This flow chart does not try and cover things like synchronized access, thread safety etc or the legacy collections, but it does cover the 3 standard Sets, 3 standard Maps and 2 standard Lists. This image was created for this answer and … Read more
The size member function. myList.size(); http://docs.oracle.com/javase/6/docs/api/java/util/ArrayList.html
You can do it like this: list.add(1, object1) list.add(2, object3) list.add(2, object2) After you add object2 to position 2, it will move object3 to position 3. If you want object3 to be at position3 all the time I’d suggest you use a HashMap with position as key and object as a value.
Use the set method to replace the old value with a new one. list.set( 2, “New” );
If you know in advance what the size of the ArrayList is going to be, it is more efficient to specify the initial capacity. If you don’t do this, the internal array will have to be repeatedly reallocated as the list grows. The larger the final list, the more time you save by avoiding the … Read more
Probably the easiest way for any list would be: listA.containsAll(listB) && listB.containsAll(listA)
There’s no difference between list implementations in both of your examples. There’s however a difference in a way you can further use variable myList in your code. When you define your list as: List myList = new ArrayList(); you can only call methods and reference members that are defined in the List interface. If you … Read more
Let arrList be the ArrayList and newValue the new String, then just do: arrList.set(5, newValue); This can be found in the java api reference here.