How to find the length of an array list? [duplicate]

问题

This question already has answers here:

How can I get the size of an array, a Collection, or a String in Java? (2 answers)

Closed 5 years ago.

I don't know how to find the length of an array list. I think you might need to use blank.length(); but I'm not sure.

I made an array list

ArrayList<String> myList = new ArrayList<String>();

but how do I write code to print out the size of myList?

回答1:

The size member function.

myList.size();

http://docs.oracle.com/javase/6/docs/api/java/util/ArrayList.html

回答2:

System.out.println(myList.size());

Since no elements are in the list

output => 0

myList.add("newString");  // use myList.add() to insert elements to the arraylist
System.out.println(myList.size());

Since one element is added to the list

output => 1

来源：https://stackoverflow.com/questions/9652732/how-to-find-the-length-of-an-array-list