ArrayList remove except if contains character

Question

Android Studio - Java

How can I remove all entries from an ArrayList except the ones that contain certain characters independently from upper and lower case?

String[] numbers = new String[] {"One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Eleven", "Twelve"};

ArrayList arrayList=new ArrayList<>(Arrays.asList(numbers));


ArrayList.remove();

E.g. if I choose the letters "Ne" I would like to remove all the entries from the arraylist except the entries containing the charachter string "ne".

Pavneet_Singh · Accepted Answer · 2017-06-12T13:43:06.687

4

In android ,for non java-8

1.) Traverse you array values

2.) Apply toLowerCase() to convert value to lowercase and Check if it contains ne , if no then remove the element from list

for (String s: numbers) {
    if (!s.toLowerCase().contains("ne")) {
        arrayList.remove(s);
    }
}

list elements

One
Nine

Java 8

1.) Never use Raw type

2.) Apply the above logic in filter

ArrayList<String> arrayList=new ArrayList<>(Arrays.asList(numbers));
List<String> non_ne = arrayList.stream()
                    .filter(x->!x.toLowerCase().contains("ne"))
                    .collect(Collectors.toList());

edited Jun 12 '17 at 13:43

answered Jun 09 '17 at 16:38

Pavneet_Singh

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This code actually worked for me! Awesome, thank you so much!! :) – LoveCoding Jun 10 '17 at 12:28
i am glad that i could help , happy coding – Pavneet_Singh Jun 10 '17 at 12:38

ΦXocę 웃 Пepeúpa ツ · Answer 2 · 2017-06-09T16:46:37.223

2

You can use a stream

arrayList.stream().filter(x -> x.indexOf("ne") !=-1).collect(Collectors.toList());

edited Jun 09 '17 at 16:46

answered Jun 09 '17 at 16:38

ΦXocę 웃 Пepeúpa ツ

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contain certain characters independently from upper and lower case – Pavneet_Singh Jun 09 '17 at 16:41
Unfortunately, this code doesn't work for me since Android doesn't allow me to use Lambda expression.. Thank you anyway for your suggestion! – LoveCoding Jun 10 '17 at 12:18
if you want `lambda` then you can use [retrolambda](https://github.com/evant/gradle-retrolambda) – Pavneet_Singh Jun 10 '17 at 12:37

score 2 · Answer 3 · answered Jun 09 '17 at 16:53

Looking at your code I am thinking you are probably better off not adding them in the first place. you are effectively saying:

String[] numbers = new String[] {"One", "Two", "Three", ...}; //array
List list = Arrays.asList(numbers) //create a list
ArrayList arrayList = new ArrayList<>(list); //create an ArrayList

//remove those not matching from the ArrayList

I would prefer the approach of only adding the ones I need to be in the list:

List<String> list = new ArrayList<>(); //a LinkedList may be more appropriate 
for (String number : numbers) {
    if (number.toLowerCase().contains("ne")) {
        list.add(number );
    }
}

This is certainly helpful in other cases, however it doesn't really solve my problem. Thank you anyway for your help! — LoveCoding, Jun 10 '17 at 12:30

score 1 · Answer 4 · answered Jun 09 '17 at 16:38

1

List <String> filtered = arrayList.stream().filter(x -> x.contains("ne")).collect(Collectors.toList());

answered Jun 09 '17 at 16:38

NiVeR

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contain certain characters independently from upper and lower case – Pavneet_Singh Jun 09 '17 at 16:41
Unfortunately, this code doesn't work for me since Android doesn't allow me to use Lambda expression.. Thank you anyway for your suggestion! – LoveCoding Jun 10 '17 at 12:26

score 1 · Answer 5 · answered Jun 09 '17 at 16:42

1

Try this:

Iterator<String> iter = arrayList.iterator();
while (iter.hasNext()) {
  String s = iter.next();
  if (s.toLowerCase().contains("ne")) iter.remove();
}

answered Jun 09 '17 at 16:42

fdelafuente

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ArrayList remove except if contains character

5 Answers5