Arrays & ArrayList

Java Arrays & ArrayList - 14 Cards

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Array

A collection of similar elements stored in contiguous memory locations

Declaring an array

int arr[] = new int[5];

Declaring and Initializing an array

int arr2[] = { 25, 30, 50, 10, 5 };

array length method

Returns the number of elements in an array in Java.

Print Array Element

System.out.println( marks[0]);

Arrays.toString (arr)

Returns a string representation of the contents of an array.

ArrayIndexOutOfBounds Exception

An error that occurs when an invalid index is used to access an array element

Arrays.fill(marks, 100)

Assigns a value of 100 to all elements of the marks array.

Arrays.equals(arr1, arr2)

Compares if two arrays have the same elements in the same order.

Arrays.sort(marks);

Sorts an array in ascending order.

ArrayList

Resizable array implementation, that allows insertion and deletion operations.

arrayList. add("XYZ")

Adds an element to the end of an ArrayList in Java.

arrayList. remove("XYZ")

Removes the first occurrence of the element "XYZ" from the ArrayList.

Array vs ArrayList

An array has a fixed size while an ArrayList has a dynamic size