Array Length and Looping

Knowing the length of an array is very useful, especially in the context of looping, or iterating.

Length

You can find the length of an array using the length attribute. An attribute is different than a function. Whereas a function requires parameters and returns a value, an attribute is simply a variable that has been made public to you.

var animals = ["cat", "dog", "bird"];
print(animals.length);

Output:

3

Note that we used animals.length, NOT animals.length().

Looping

When you know the length of an array, you can use a for loop to access each element. The following code prints each element of the animals array in order.

for (var i = 0; i < animals.length; i += 1) {
    println(animals[i]);
}

Output:

cat
dog
bird