Question

I have a List at java. My class has fields and one of them is: name. Lets assume that:

List<MyClass> mylist = new ArrayList<MyClass>();
MyClass myElement = new MyClass();
myElement.setName("xxx");

So how can I check is there any element at List which contains same name with myElement variable and retrieve that variable?

Answer 1

If your MyClass implements equals() in a way that makes two MyClass instances equal if they have the same name, then you can simply do:

int index = mylist.indexOf(myElement);
MyClass myListElement = mylist.get(index);

Unfortunately there is no “get the element that is equal() to this” method in the Collection/List API, which could be implemented in a more efficient manner.

If you don’t have such a equals() implementation (or don’t want it for some reason), then you’ll have to do it the boring, old-fashioned way:

MyClass listElement = null;
for (MyClass mc : mylist) {
  if (myElement.getName().equals(mc.getName()) {
    listElement = mc;
    break;
  }
}
// if listElement is non-null here, then we found it