I have a known object property value, how to find the index in the collection

Question

Student a=new Student(“jack”)
Student b=new Student("Lily")

list<Student> list=new ......;
list.add(a);
list.add(b);

now i want to move "jack"，it can use like this，

list.remove(0);

but sometimes i dont know where the index of " jack" in the list ，how can i find it and remove it ，can you help me ？i think 3hours over！

Answer 1

You get the index of the element from the indexOf method. Or you just pass the object to remove to the remove method. Both work fine.

A comment on your code: List is an interface, you can't instantiate an interface, the right side needs a concrete class, like this:

List<Student> students = new ArrayList<>();

Interface on the left side, implementation on the right side.

Answer 2

https://code.sololearn.com/c5iUuc9c8li8/?ref=app