Creating a 1D array of integers and initializing it:

int[] arr = (a)   int[]{1, 2, 3, 4, 5};

Creating a 2D array of strings and initializing it:

String (a)   arr = new String[][]{

{John, Doe},

{Jane, Doe},

{Bob, Smith}};

Accessing an element of a 1D array by index:

int[] arr = new int[]{1, 2, 3, 4, 5};

int value = arr[ (a)   ]; // value will be 3

Accessing an element of a 2D array by row and column index:

String[ ][ ] arr = new String[ ][ ]

{"John", "Doe"},

{"Jane", "Doe"},

{"Bob", "Smith"} };

String value = arr (a)   ; // value will be "Jane"

Usage of foreach loop in java

String[] cars = {"Volvo", "BMW", "Ford", "Mazda"};

for (String i : cars) {

System.out.println( (a)   ); //display all the values of cars }

Creating an ArrayList of integers and adding elements to it:

(a)   <Integer> list = new ArrayList<Integer>();

list.add(1);

list.add(2);

list.add(3);

Creating an ArrayList of strings and adding elements to it:

ArrayList<String> list = new ArrayList<String>();

list.________________("apple");

list.________________("banana");

list.________________("cherry");

(a)  

Removing an element from an ArrayList by index:

ArrayList<String> list = new ArrayList<String>();

list.add("apple");

list.add("banana");

list.add("cherry");

list.remove( (a)   ); // removes the element at index 1 (banana)

Checking if a String contains a substring:

String str = "Hello, world!";

boolean containsSubstring = str. (a)   ("world"); // containsSubstring will be true

Concatenating two strings:

String str1 = "Hello";

String str2 = "world";

String result = (a)   + “ “ + str2; // result will be "Hello world”