How to check whether String already exist in Arraylist?

Question

I have an app in which contain ArrayList of some String let suppose a,b,c,d and i have a String called pack. What i have to do is that i have to check whether pack is already exist in arraylist or not if not exist then i have to add it in arraylist. How do i do that

code:-

ArrayList<CBlackList> appsListDataSet;
 public void setAppsDetails(String pack) {
    if (appsListDataSet != null && appsListDataSet.size() > 0) {
        for (int i = 0; i < appsListDataSet.size(); i++) {
            CAppsModel appsModel = appsListDataSet.get(i);
            if (pack.equalsIgnoreCase(appsModel.getPackageName())){
                //Not to know what to do here.
            }
        }
    } 
}

check https://stackoverflow.com/a/2642709/3981656 – Sathish Kumar J Aug 21 '17 at 11:11 — Sathish Kumar J, Aug 21 '17 at 11:11
use `yourArrayList.contains("pack")` method – Pallavi Tapkir Aug 21 '17 at 11:12 — Pallavi Tapkir, Aug 21 '17 at 11:12

score 1 · Answer 1 · answered Aug 21 '17 at 11:11

1

Use the contains method in an arrayList. If your arrayList contains only String and you want to check for String value itself, then just do

boolean isPackPresent = appsListDataSet.contains(pack)

this will work if your arraylist has the same datatype as pack and is not a custom object.

answered Aug 21 '17 at 11:11

Kapil G

4,081
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My ArrayList takes – Niraj Aug 21 '17 at 11:13
Then you need to implement the equals method for your class CBlackListModel. Check the link which is mentioned as the duplicate to your issue – Kapil G Aug 21 '17 at 11:19
where is the link – Niraj Aug 21 '17 at 11:20
https://stackoverflow.com/questions/2642589/how-does-a-arraylists-contains-method-evaluate-objects – Kapil G Aug 21 '17 at 11:21
I only have to check whether ArraList contain "pack" if found then break the loop else add it to db – Niraj Aug 21 '17 at 11:23

score 1 · Answer 2 · answered Aug 21 '17 at 11:11

1

Try Some thing like this

if(appsListDataSet.contains("your String"))
{
 ///Action to be occur
}

answered Aug 21 '17 at 11:11

Anil

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How to check whether String already exist in Arraylist?

2 Answers2