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java – Remove a String Item from a List of Strings

Posted by: admin June 15, 2020 Leave a comment

Questions:

How do I remove a specific string from a List that contains Strings….

As in:

ArrayList<String> myStrings = new ArrayList<>();
myStrings.add("Alpha");
myStrings.add("Beta");
myStrings.add("Gama");
.                           //The order can be random 
.
.
.

Now , I only have the list myStrings and I don’t know which String is at which index. But I know, that I want to display all the strings after removing say “Alpha”.

To Summarize , How can I get the strings from a String array after removing a String that I know that array contains , but don’t know its index/position.

How to&Answers:

Use remove :

myStrings.remove("Alpha");

Note that this would only remove the first occurrence of “Alpha” from your list.

Answer:

boolean remove(Object o)

The above method of ArrayList class will remove the first occurence of Object o from the list.

You can do:

myStrings.remove("Alpha");

It will return true if the ArrayList contained the specified element.

Answer:

Do you have duplicates in the list of String that you also wish to remove?

If so, you can convert the list of String into a set of String. Then, you can remove strings from the set efficiently, convert it back into a map.

// converting to set will remove duplicates
final Set<String> uniqueStrSet = new HashSet<String>(listOfString);

// remove string from set
uniqueStrSet.remove(strToRemove);

// convert set back to list
list = new ArrayList<String>(uniqueStrSet);