how to check with ArrayList 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,

score 1 · Accepted Answer · edited May 23 '17 at 12:12

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 '17 at 12:12

Community

1
1

answered Nov 01 '12 at 05:01

Abhishek Sabbarwal

3,758
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I tried with this, theres no problem in adding, but while removing , error occurs.. – Vishnu Nov 01 '12 at 05:06
what exactly does your code look like when you tried with this method ? and what error are you getting ? – Abhishek Sabbarwal Nov 01 '12 at 05:08
YOur code help me get it out the expected output. thanks. but small change is there. – Vishnu Nov 01 '12 at 05:19

how to check with ArrayList for inserting and deleting in android

1 Answers1