Why arrays are needed in Java - Challenge Your Understanding

trophy

Challenge - 5 Problems

🧠 conceptual

intermediate

Why use arrays instead of individual variables?

Imagine you want to store the scores of 5 students. Why is using an array better than using 5 separate variables?

A Arrays allow storing multiple values under one name, making code simpler and easier to manage.

B Arrays automatically sort the values for you without extra code.

C Arrays use less memory than individual variables.

D Arrays prevent any changes to the stored values once set.

💻 code output

intermediate

Output of array element access

What is the output of this Java code?

Java

int[] numbers = {10, 20, 30, 40, 50};
System.out.println(numbers[2]);

A 10

B 30

C 20

D 40

💻 code output

advanced

What happens when accessing array out of bounds?

What error does this Java code produce?

Java

int[] arr = {1, 2, 3};
System.out.println(arr[3]);

A ArrayIndexOutOfBoundsException

B NullPointerException

C No output, prints 0

D SyntaxError

🚀 application

advanced

How many elements are in this array?

Given this Java array declaration, how many elements does it contain?

Java

String[] fruits = new String[7];

A 6

B 8

C 7

D 0

🧠 conceptual

expert

Why arrays improve program efficiency?

Which reason best explains why arrays improve efficiency in programs?

A Arrays prevent any data from being changed once stored.

B Arrays automatically compress data to save space.

C Arrays allow storing different data types together for flexibility.

D Arrays store data in contiguous memory locations, allowing fast access by index.