Java – what is the difference between length and length?

See English answer > length and length () in java7

arrayone.length;

However, for things like array lists or strings, you end up with a bracket. For example, the length of string is as follows:

stringone.length();

What is the key reason and how do you know when to put parentheses or now?

Solution

.length;

.length;

Direct access to a field member

.length();

Calls a method (i.e., accessor) that accesses a farm member

In the case of string, this is expected because it is immutable