We Keep Coding

is there way to select everything from a list of model?

asnafList is my list and getIc_number is my getter below is my code
asnafList.get(0).getIc_number();
I am trying to make sort of an authenticating feature for my apps and I use the above code in my if statement for the button. That code only get the 0 position of the list. So my question is, is there a way to get all of the position is the list to compare with the input from the user using the if statement?

int number;
for(int i = 0; i < asnafList.size(); i++) {
number = asnafList.get(i).getIc_number();
if(number == YOUR_COMPARABLE_NUMBER) {
// Compare and do anything here
}
}

As Kushal answered, a for loop is useful for this. But I usually use a for each loop in this scenario. Not sure what type of objects are in the asnafList, but it will look something like this:
for(AsnafObject a : asnafList) {
if(a.getIc_number() == YOUR_COMPARABLE_NUMBER) {
// do stuff
}
}
When you do this for loop, you basically iterate through every object in the asnafList, where AsnafObject is the classtype of your asnafList and a is the object which you can use to call any non-static methods of AsnafObject (or however your class is called)

Including new elements in for:each

Before I start my question, i'd like to mention that i DID read up some other topics and i tried around a bit but im just really confused atm so i figured i'd just ask.
So what i wanna do is use for each through a Set and within that for each, add elements to that set and also iterate through those.
The solution I found elsewhere was the following:
for(Object obj : new HashSet<Object>(oldSet))
I tried that, however I keep missing some of the last elements i'd like to match so im not really sure if this is the right approach in the first place?
To be specific, this is basically what my code looks like:
for(Position pos : new HashSet<Position>(oldSet){
for(Delta delta : deltas){
if(board.getTokenAt(pos.plus(delta).equals(initial){
hitList.add(pos.plus(delta);
oldSet.add(pos.plus(delta);
}
}
oldSet.remove(pos);
}
Again, I'd just like to know if my approach is wrong or there must be an error elsewhere in my code so i know what to look at.
Thanks beforehand!

You can't really add to a data structure while iterating over it, that is almost guaranteed to have unexpected results.
However, there is a simple enough solution to your issue. Just process each item recursively when you find that it needs to be added, and add it to a separate List. At the end of iteration, add everything in the List to the main Set. This avoids the issue of adding during iteration while still allowing you to to process the newly added items.
It would look something like this:
List<Position> toAdd = new LinkedList<>();
for(Position pos : oldSet){
for(Delta delta : deltas){
addIfGoodAndRecurse(pos, delta, toAdd);
}
}
And then you can use this helper method to add the item if it meets your conditions and also recursively process added items. Note you will need to change the method signature to pass in your board, initial, and hitList if they are local variables. I didn't know their types or whether they were global variables or fields, so I couldn't really add them in the example.
private void addIfGoodAndRecurse(Position pos, Delta delta, List<Position> toAdd) {
Position toCheck = pos.plus(delta);
if(board.getTokenAt(toCheck.equals(initial))) {
hitList.add(toCheck);
toAdd.add(toCheck);
for (Delta recursionDelta : deltas) {
addIfGoodAndRecurse(toCheck, recursionDelta, toAdd);
}
}
}
I don't have your code, so I can't test this. The idea should work fine, but you may need to make slight modifications.

You can iterate through new elements added to a list that you're iterating if you add them to the end of the list and iterate through it using an index and the get() method, not through an Iterator. You can also use the Set as you are doing now, but only to make sure you only add unique items to your collection.
List<Position> list = new ArrayList<>(oldSet);
for (int i = 0; i < list.length; ++i) { // NB list.length could be different each time
Position pos = list.get(i);
for(Delta delta : deltas){
if(board.getTokenAt(pos.plus(delta).equals(initial){
hitList.add(pos.plus(delta));
if (oldSet.add(pos.plus(delta))) // Check if it already exists in the list
list.add(pos.plus(delta));
}
}
oldSet.remove(pos);
}

Returning an arraylist and iterating throught the returned list

Im trying to return an arraylist from the method getNumbers (which contains strings)
public ArrayList<String> getNumbers(){
return (numeros);
}
Then by using a searcher im trying to compare between a variable m (which contains the desired info to look for) and the returned list.
public class NumberSearcher {
Reader reader = new KeyboardReader();
public NumberSearcher(ArrayList<Contacto> contactos){
String m = reader.read();
for(int i = 0; i<contactos.size();i++){
if(contactos.get(i).getPhoneNumbers().contains(m)){
contactos.get(i).display();
}
}
}
}
I have succeded in creating a searcher using this very same style but only when using methods that return String alone.
The problem is its not working. If there there would be a match it should display the contact information but it seem it isnt "comparing" properly because nothing happens.

It's difficult to understand what you're asking here. Your getNumbers method doesn't get called from the second code block, so I don't see where that is relating to anything. It's also unclear what you mean the problem is. Can you try to give us a more detailed description of what is going wrong?
Anyways, I'll try to give you some general advice here, but without knowing the issue it's hard to say how much this will help.
Firstly, it is almost always recommended to have your method's return type as the List interface, rather than a specific implementation (ArrayList, etc). You can specify a return type from within the method but this way they client doesn't need to know what the underlying data structure is, and you are also flexible to future data structure changes.
public List<String> getNumbers(){
return (numeros);
}
Secondly, I would probably change the name 'getNumbers' to something slightly more precise - if I see a 'getNumbers' method I expect it to return some numeric entities, not a list of strings. If they are phone numbers then explicity call it 'getPhoneNumbers'.
Though I'm not entirely sure I understand what you asking, I think this may solve your issues:
for(int i = 0; i < contactos.size(); i++) {
Contacto next = contactos.get(i);
if(next.getEmails().contains(m)) {
next.display();
}
}
And as an afterthought, is there any specific reason you're only checking string containment? I would suggest that you check case-insensitive equality unless you really do want to find out if the string just contains the element.

Is this what you are looking for?
public class EmailSearcher {
Reader reader = new KeyboardReader();
public EmailSearcher(ArrayList<Contacto> contactos){
while(reader.read() != 'keyThatTerminates') {
String m = reader.read();
for(int i = 0; i<contactos.size();i++){
var row = contactos.get(i);
if(row.getEmails().contains(m)){
row.display();
}
}
}
}
}

Making an add method for an ArrayList

So I am supposed to make an add method for an array list which adds a new movie object to the list if it doesnt exist, or if it finds a movie object with a similar title within the list, it just increases the quantity property of that object. Here is what I've got so far.
public void add(String title, double rating, int releaseYear){
if(this.myMovies.size() < 1)
{
Movie mymovie = new Movie(title, rating, releaseYear);
this.myMovies.add(mymovie);
}
else
{
for(int i = 0; i < this.myMovies.size(); i++)
{
Movie temp = this.myMovies.get(i);
if(temp.Title.equals(title)){
this.myMovies.get(i).quantity++;
break;
}
else
{
Movie mymovie = new Movie(title, rating, releaseYear);
this.myMovies.add(mymovie);
break;
}
}
}
}
My problem is that this ends up not taking account of similar names and doesn't increase the quantity but just adds another object to the list. I have a strong feeling that the problem lies within my For loop but I just can't identify it. Can anyone see anything that I may be doing wrong? Thank you!

You're testing only for equality, not similarity here:
if(temp.Title.equals(title)){
Instead, you should write a helper method to test for similarity based on whatever criteria are appropriate. For example:
if (isSimilar(temp.Title, title)){
and the isSimilar method might look something like this (assuming you don't need any input validation):
private void isSimilar(String title1, String title2) {
return title1.equalsIgnoreCase(title2)
|| title1.toLowerCase().contains(title2.toLowerCase())
|| title2.toLowerCase().contains(title1.toLowerCase());
}
or, perhaps more appropriately, like this (if you implement it in the Movie class):
private void isSimilar(otherMovie) {
return title.equalsIgnoreCase(otherMovie.title)
|| title.toLowerCase().contains(otherMovie.title.toLowerCase())
|| otherMovie.title.toLowerCase().contains(title.toLowerCase());
}
...in which case your if statement would also change slightly.
Keep in mind that I don't know what you consider 'similar'; only that the movies are considered similar if the names are similar.
A couple more comments:
Fields and method names generally start with a lowercase letter (so the field Movie.Title should instead be Movie.title).
It's usually preferable to loop over a Collection using an Iterator instead of using the raw index--partly because the Iterator should always know how to loop over the Collection efficiently.
Learn to use your IDE's debugger (it's probably very easy). Then you can step through each line of code to see exactly where your program is doing something unexpected.

I would do something like this:
public void add(String title, double rating, int releaseYear){
for(Movie m: myMovies.size())
{
if(m.Title.equals(title)){
m.quantity++;
return;
}
}
// movie with same title not found in the list -> insert
this.myMovies.add(new Movie(title, rating, releaseYear));
}
By the way: variable names should start with a lowercase character (Title -> title).

I'm addressing your "similarity" requirement. If you really want to do this properly it could be a lot of work. Essentially you have two strings and want to get a measure of the similarity. I am doing the same thing for figure captions and I plan to tackle it by:
splitting the title into words
lowercasing them
using them as features for classifier4J (http://classifier4j.sourceforge.net/)
That will go a long way based on simple word counts. But then you have the problem of stemming
(words that differ by endings - "Alien" and "Aliens"). If you go down this road you'll need to read up about Classification and Natural Language Processing

Java is not assigning values to my variables correctly, with linked lists

public void returnRental(Customer cust){
Rental toDelete = null; //Rental to be removed from list.
LinkedList<Video> toReturn = null; //List of videos to be added to inventory.
//Find appropriate rental according to customer name.
for(int i = 0; i < rentals.size(); i++){
if(cust.getName() == rentals.get(i).getRentee().getName()){
toReturn = rentals.get(i).getRented();
toDelete = rentals.get(i);
}
}
here is the snippet of code that is giving me problems. I've debugged it in eclipse quite a bit which ended up just confusing me more. It hits the if, and passes the condition. But once it gets to assigning values to "toReturn" it assigns it an empty list with size 0. Where as I check my rentals Linked list and the correct value are there, but for some reason it is not getting assigned to my variables correctly :( The same happens to "toDelete" but this isn't a list, it is one instance of my class Rental. (The linked list is a list of rentals, which contains a linked list of videos)
No errors are thrown...
Its a little difficult to explain, if you need more information please let me know and i'll clarify.
I'm at a loss, possibly because I'm not iterating through my linked list correctly?

Replace
if (cust.getName() == rentals.get(i).getRentee().getName()){
by
if (cust.getName().equals(rentals.get(i).getRentee().getName())){
You can't compare strings with == (except if your algorithm can ensure this is the same instance, which is almost never the case).
But the missing equals is not the only bug. It may be inside getRented() or elsewhere (you don't show what you do with toReturn and toDelete, so it's not clear if you don't have problems here).
Now, to go on chasing your bugs, you should either
debug, and put a breakpoint in your loop to check the state of rentals.get(i) and the execution at this point
if you can't debug, put a lot of System.println, so that you know what you have...

I've upvoted dystroy's answer because incorrect string comparison is always wrong.
But because that would fail differently (customer names not matching rentee names), I'm wondering if your issue is really caused by either of the following:
a problem in getRented(); or
cust having a null name on call, which would match a Rentee with a null name.

Possibly, your if condition is being hit more than once. First of all, check if this is actually happening. If so, check your logic and determine if you want to stop at the first occurence or at the last (this case seems to be the latter).
If you want to stop at the first occurence, break the iteration:
for(int i = 0; i < rentals.size(); i++){
if(cust.getName() == rentals.get(i).getRentee().getName()){
toReturn = rentals.get(i).getRented();
toDelete = rentals.get(i);
break;
}
}

for(int i = 0; i < rentals.size(); i++){
if(cust.getName().equals( rentals.get(i).getRentee().getName())){
toReturn.addAll(rentals.get(i).getRented());
//assumming it returns the list of Video object
toDelete = rentals.get(i);
}
}