Java arrays

Array

An elementary data structure that holds elements in a contiguous block of memory.

0-indexed

A method of indexing where the first element of an array is at index 0.

Array Initialization

In Java, creating an array will auto-initialize elements to the zero/null equivalent.

2D Array

An array that contains arrays, often visualized as a table with rows and columns.

Arrays Class

A utility class in Java that provides methods for array manipulation, such as sorting and converting to String.

ArrayList

A resizable array implementation in Java that can hold items and automatically adjust its size.

size() method

Returns the number of elements currently stored in an ArrayList.

add() method

Appends a given value to the end of an ArrayList.

remove() method

Removes the first occurrence of a given value from an ArrayList.

copyOf() method

Creates a new array with a specified length, copying the contents of the original array.

fill() method

Fills an array with a specified value.

Arrays.toString() method

Returns a String representation of the contents of an array.

isEmpty() method

Checks whether an ArrayList has no elements.

indexOf() method

Returns the index of the first occurrence of a specified value in an ArrayList.

clear() method

Removes all elements from an ArrayList, setting its size to 0.

shallow copy

Creating a new reference to an existing array, meaning changes will reflect in both references.

deep copy

Creating a new array that duplicates the contents of an original array.

traversal

The process of accessing each element in an array or collection.

for-each loop

A loop that iterates over the elements of an array without using index variables.

Array access

To retrieve an element from an array using its index.

Random Class

A class in Java used to generate random numbers.