Variables
Arrays in Java
Arrays are used to assign a series of elements of the same type in consecutive memory locations; to define a list of elements. They work similar to variables, except they contain multiple values at different indices.
Syntax
dataType[] arrayName;
arrayName = new dataType[arraySize];
arrayName[index] = arrayElement; //storing to an array element
Notes
dataType can be any Java data type. arrayName is defined by the programmer. arraySize and arrayElement are integers. arrayValue depends on the assigned data type and is defined by the programmer.
Each element stored in an array is given an index, which allows you to access that element using square brackets.
Arrays are initialized with a size. The array index range is 0 to the initialized size minus 1. This means that the first index in the array is 0, and the last is size minus 1. Trying to access an index outside the index range will result in an error.
Like regular variables, array variables can be declared first, and initialized later.
Access modifiers can be included in array initialization.
A matrix (array defined by rows and columns) can also be created in the same way by adding a second set of square brackets where required (dataType[rows][columns]).
Dynamically sized arrays can be created using the ArrayList class.
Example
int[] array = new int[2]; //declaring an array of size 2
array[0] = 1; //storing a value of 1 in the first element
array[1] = 2; //storing a value of 2 in the second element
