Массивы

Одномерные

int [] numbers ;
String [] args ;
boolean bits [];

int [] numbers = new int [100];
String [] args = new String [1];
boolean [] bits = new boolean [0];

int [] numbers = new int [] {1, 2, 3, 4, 5};
boolean [] bits = new boolean [] {true , false };
// this works only in variable declaration
char [] digits = {
’0’, ’1’, ’2’, ’3’, ’4’,
’5’, ’6’, ’7’, ’8’, ’9’};

int [] numbers = {1, 2, 3, 4, 5};
int arrayLength = numbers . length ;
int firstNumber = numbers [0];
int lastNumber = numbers [ arrayLength - 1];
int indexOutOfBounds = numbers [5];

Многомерные

int [][] matrix1 = new int [2][2];
int [][] matrix2 = {{1 , 2}, {3, 4}};
int [] firstRow = matrix2 [0];
int someElement = matrix2 [1][1];

int [][] triangle = {
{1, 2, 3, 4, 5},
{6, 7, 8, 9},
{10 , 11, 12} ,
{13 , 14} ,
{15}};
int secondRowLength = triangle [1]. length ;

Varargs

static int maxArray (int [] numbers ) { ... }
static int maxVarargs (int ... numbers ) { ... }

Сравнение массивов

int [] a = {1, 2, 3};
int [] b = {4, 5, 6};
boolean equals1 = a == b;
boolean equals2 = a. equals (b);
boolean equals3 = Arrays . equals (a, b);
boolean equals4 = Arrays . deepEquals (a, b);

Вывести элементы массива

int [] a = {1, 2, 3};
System . out. println (a);
System . out. println ( Arrays . toString (a));
System . out. println ( Arrays . deepToString (a));