how to check with ArrayList<Integer> for inserting and deleting in android

Question

I have ArrayList as "deletedPositions", and im passing Value into that arrayList, before that i want to check wheather value is present in that array, if yes then i want delete that value, if not present , then add the value in that array List, How this CAn be done?

I tried with this code, but unable to get answer,

        if(deletedPositions.isEmpty())
    {
        deletedPositions.add(PositionChecked);
        Toast.makeText(getApplicationContext(), "Is empty ="+this.deletedPositions.size(), 1).show();
    }
    else
    {
        for(int i=0;i<deletedPositions.size();i++)
        {
            if(deletedPositions.get(i) == PositionChecked)
            {
                deletedPositions.remove(i);
                Toast.makeText(getApplicationContext(), "After removeArray ="+this.deletedPositions, 1).show();
            }
            else
            {
                deletedPositions.add(PositionChecked);
                Toast.makeText(getApplicationContext(), "After Added Array ="+this.deletedPositions, 1).show();
            }
        }
    }

Anyone help me to overcome this.. Thanks in advance,

Community · Accepted Answer · 2017-05-23 12:12:13Z

1

You have to use the arraylist.contains method to check if the element is already present in the arraylist. You donot need a for loop to run through the entire arraylist. Use the following :

if(deletedPositions.contains(PositionChecked)) {
    int numIndex = deletedPositions.indexOf(PositionChecked)  
    deletedPositions.remove(numIndex);  
}
else {
    deletedPositions.add(PositionChecked);
}

Also you can refer the following thread Check if a value exists in ArrayList

edited May 23, 2017 at 12:12

CommunityBot

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answered Nov 1, 2012 at 5:01

Abhishek Sabbarwal

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3 Comments

Vishnu Over a year ago

I tried with this, theres no problem in adding, but while removing , error occurs..

Abhishek Sabbarwal Over a year ago

what exactly does your code look like when you tried with this method ? and what error are you getting ?

Vishnu Over a year ago

YOur code help me get it out the expected output. thanks. but small change is there.

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