you have two approaches:
ArrayList<String> ar = new ArrayList();
ar.add("UserId"); //adding item to arraylist
ar.add("Directory");
ar.add("Username");
ar.add("PhoneNumber");
// approach one using iteration
for (Iterator<String> it = ar.iterator(); it.hasNext(); ) {
String f = it.next();
if (f.equals("UserId"))
System.out.println("UserId found");
}
// approach two using a colletion which supports fetching element by key
Map<String,String> myMap=new HashMap<>();
for(String strg:ar){
myMap.put(str,str);
}
String result=myMap.get("UserId");
If you have repeating element (for example several “UserId” element), you can use collections that support bags (sets with duplicate elemets), for example guava mutiset
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solved how to get substring items with in arraylist in java