[FIXED] How to remove item from list in Android

Issue

In my application I have 2 list and maybe some items same between lists.
I want to check these lists and remove same items.
I write below codes but after run application show me error and crashed application!
My codes:

if (ALLERGIC_LIST.isNotEmpty()) {
    ALLERGIC_LIST.forEach { allergic ->
        //Added to user list
        userLocalList.add(LocalDataModel(allergic.faName.toString(), true, 0, allergic.id!!))
        userRecyclerView.adapter!!.notifyDataSetChanged()
        //Remove from temp list
        dataListTemp.forEach { temp ->
            Log.e("AllergicLogs","${allergic.id} - ${temp.id}")
            if (allergic.id == temp.id) {
                dataListTemp.remove(temp)
            }
        }
    searchList.adapter!!.notifyDataSetChanged()
    }
}

Error message in Logcat:

2022-10-13 08:44:07.617 11990-11990/com.myapp E/AllergicLogs: 1791538835 - 1749914577
2022-10-13 08:44:07.617 11990-11990/com.myapp E/AllergicLogs: 1791538835 - 1762590770
2022-10-13 08:44:07.617 11990-11990/com.myapp E/AllergicLogs: 1791538835 - 1791538835
2022-10-13 08:44:07.617 11990-11990/com.myapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.myapp, PID: 11990
    java.util.ConcurrentModificationException
        at java.util.ArrayList$Itr.next(ArrayList.java:831)
        at com.myapp.AllergicFragment.onViewCreated$lambda-14$lambda-7(AllergicFragment.kt:233)
        at com.myapp.AllergicFragment.$r8$lambda$VH4SurM8Hl44Zx-Iy-J2iPtdh8g(AllergicFragment.kt)
        at com.myapp.AllergicFragment$$ExternalSyntheticLambda3.onChanged(D8$$SyntheticClass)
        at androidx.lifecycle.LiveData.considerNotify(LiveData.java:133)
        at androidx.lifecycle.LiveData.dispatchingValue(LiveData.java:151)
        at androidx.lifecycle.LiveData.setValue(LiveData.java:309)
        at androidx.lifecycle.MutableLiveData.setValue(MutableLiveData.java:50)
        at androidx.lifecycle.LiveData$1.run(LiveData.java:93)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6121)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:889)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:779)

How can I fix it and remove same item?

Solution

dataListTemp.forEach { temp ->
            Log.e("AllergicLogs","${allergic.id} - ${temp.id}")
            if (allergic.id == temp.id) {
                dataListTemp.remove(temp)// Here is the error. You're doing concurrent modification here
                dataListTempDuplicate.remove(temp)//Instead delete from duplicate array
            }
        }

Answered By - Ammar Abdullah
Answer Checked By - David Goodson (JavaFixing Volunteer)