exam

Question 1

What is a return type in a method?

Answer 1

Example: int, double, String, boolean, etc. If the method does not return any value, the return type is void.

Question 2

syntax of declaring a method:

Answer 2

public void methodName(parameters) { // method body }

Question 3

.length method:

Answer 3

The .length method is used to get the length of arrays and strings in Java.

Question 4

.substring() method:

Answer 4

The .substring() method is used to extract a substring from a string.

Question 5

.toUpperCase() method:

Answer 5

The .toUpperCase() method is used to convert all characters in a string to uppercase.

Question 6

.toLowerCase() method:

Answer 6

The .toLowerCase() method is used to convert all characters in a string to lowercase.

Question 7

.equals() method:

Answer 7

The .equals() method is used to compare the contents of two strings.

Question 8

.indexOf() method:

Answer 8

The .indexOf() method is used to find the index of a specified character or substring within a string.

Question 9

How to create an ArrayList?

Answer 9

ArrayList<Type> listName = new ArrayList<Type>();</Type></Type>

Question 10

Adding elements to an ArrayList:

Answer 10

Elements can be added to an ArrayList using the add() method:

Question 11

Getting the size of an ArrayList:

Answer 11

the size() method:

Question 12

Accessing elements in an ArrayList:

Answer 12

get() method and specifying the index:

Question 13

Checking if an ArrayList contains an element:

Answer 13

using the contains() method:

Question 14

Syntax of a for loop:

Answer 14

for (initialization; condition; update) {

Question 15

Nested for loops:

Answer 15

You can have one or more for loops inside another for loop.
Useful for iterating over multi-dimensional arrays or performing repetitive tasks.
for (int i = 0; i < 3; i++) {
for (int j = 0; j < 3; j++)

Question 16

What is a while loop in Java?

Answer 16

A while loop in Java is a control flow statement that repeatedly executes a block of code as long as a condition is true.

Question 17

while loops syntax

Answer 17

while (condition) {

Question 18

Difference between for and while loops:

Answer 18

For loops are used when the number of iterations is known.
While loops are used when the number of iterations is not known beforehand or when looping based on a condition.

Question 19

When to use while loops:

Answer 19

While loops are often used when you want to repeat a block of code until a specific condition is met, such as reading input until the user enters a certain value.

Question 20

Arrays:

Answer 20

An array in Java is a fixed-size data structure that stores elements of the same type sequentially in memory.

Question 21

arrays example

Answer 21

int[] numbers = new int[5];

Question 22

Accessing Elements:

Answer 22

Elements in an array are accessed using an index.

Question 23

Accessing elements using a for loop for array

Answer 23

for (int i = 0; i < numbers.length; i++) {
System.out.println(numbers[i]);

Question 24

ArrayList:

Answer 24

ArrayList is a dynamic array implementation of the List interface in Java that allows resizing and manipulation of elements.

Question 25

array list of Declaration:

Answer 25

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