AP CSA arrays key terms

What is an array?

An array is a collection of elements, all of the same type, stored at contiguous memory locations.

True or false: Arrays can store different data types.

False, because arrays are homogeneous and must contain elements of the same type.

Define the index of an array.

The index refers to the position of an element in an array, starting from 0.

Difference between 1D and 2D arrays.

1D arrays are linear lists, while 2D arrays are grids (rows and columns).

What is the length property of an array?

The length property returns the number of elements in an array.

Fill in the blank: An array is initialized using ________.

Array literal syntax or the 'new' keyword.

Accessing an element at index 3 of an array?

Use arrayName[3] to access the fourth element.

What does 'arrayName.length' return?

It returns the total number of elements in the array.

True or false: Arrays can be resized after creation.

False, because arrays have a fixed size once initialized.

What happens when you access an out-of-bounds index?

It throws an ArrayIndexOutOfBoundsException at runtime.

Difference between an array and an ArrayList.

Arrays have a fixed size; ArrayLists can dynamically resize.

What is a multi-dimensional array?

An array that contains arrays as its elements, e.g., a 2D array.

How to declare an integer array?

int[] arrayName = new int[size]; or int[] arrayName = {value1, value2};

What is the default value of an uninitialized int array?

All elements are initialized to 0 by default.

Fill in the blank: The first element of an array is at index ________.

0.

How do you loop through an array?

Use a for loop: for (int i = 0; i < array.length; i++) {...}

True or false: Arrays can hold primitive data types.

True, because arrays can store any type, including primitives.

What is an array initializer?

Syntax used to initialize an array at the time of declaration.

What is the output of array[0] if array = new int[]{1,2,3}?

The output will be 1, the first element of the array.

Describe how to pass an array to a method.

Declare the parameter as the same type: 'void methodName(int[] array)'.

What is a jagged array?

An array of arrays where each sub-array can have different lengths.

Difference between static and dynamic arrays.

Static arrays have fixed sizes; dynamic arrays can change size.

Fill in the blank: An array's elements can be accessed using the ________ operator.

Index operator [].