In Java, why do arrays use length and not length()?

Hi Yichao,

In Java, length for an array is a field (a value stored in the array), not a method. That is why you write it without parentheses:

int[] nums = {1, 2, 3};
System.out.println(nums.length);  // 3

Parentheses are only used for methods. For example, strings use a method:

String s = "abc";
System.out.println(s.length());  // 3

So the simple rule is: arrays use length, strings use length().

If you have more questions, I am here to help 😊