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Using indexOf() method for ArrayList of objects

stackoverflow.com › questions › 69329988 › using-indexof-method-for-arraylist-of-objects

First using stream we will Iterate through hospitals list,

find out the hospital from the list whose name equals currentHospital name, take out the first result using findFirst.

Since the result may be or may not be available it returns Optional. So on Optional, we will say if it's (the hospital object which we were looking for) present we will get the hospital out of it using the get method

Optional<Hospital> result = hospitals.stream().filter(h -> h.nameHospital.equals(currentHospital)).findFirst();

if(result.isPresent()){
    Hospital hospital = result.get();
}

Answer from navnath on Stack Overflow

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Java ArrayList indexOf() Method

public int indexOf(Object item) Java Arrays Tutorial · Java ArrayList Tutorial · ❮ ArrayList Methods · ★ +1 · Sign in to track progress · REMOVE ADS · PLUS · SPACES · GET CERTIFIED · FOR TEACHERS · BOOTCAMPS · CONTACT US · × · If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: sales@w3schools.com ·

Oracle

docs.oracle.com › javase › 8 › docs › api › java › util › ArrayList.html

ArrayList (Java Platform SE 8 )

April 21, 2026 - Java™ Platform Standard Ed. 8 ... public class ArrayList<E> extends AbstractList<E> implements List<E>, RandomAccess, Cloneable, Serializable

Discussions

java - Using indexOf() method for ArrayList of objects - Stack Overflow

In my program, I have a Vendor class and a Hospital class and store instances of these classes in arraylists called vendors and hospitals. My Vendor class has a string array with names of hospitals... More on stackoverflow.com

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A better way to find the index of an element in an array?

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r/javahelp

August 27, 2022

Arraylist indexof

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Java ArrayList IndexOf - Finding Object Index - Stack Overflow

ArrayList holder = new ArrayList; Data one = new Data(0,0); Data two = new Data(0,4); Data three = new Data(0,5); ... Is indexOf any better than going through the whole array list myself? Or am I missing something. ... The problem is you are not overriding equals method but overloading instead. ... The indexOf() method does go through the entire list. Here's an excerpt from Java ... More on stackoverflow.com

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