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Arrays Overview

Why Arrays Got Introduced?

Can arrays be replaced with primitives? This lesson teaches how arrays enhance algorithm performance and substitute primitive data types.

Let's take a step back and consider why we need arrays in the first place. 🤔

Why not make use of primitives?

In Java int takes 4 bytes. So, the declaration below occupies 4 bytes of memory.

int a = 100;

What if we want to store six int values (or 24 bytes)? We need to use six different variables individually, each occupying 4 bytes so that the total will be 6 * 4 = 24 bytes.

// each of the following occupies 4 bytes, which is 6 * 4 bytes
int a1 = 100;
int a2 = 200;
int a3 = 300;
int a4 = 400;
int a5 = 500;
int a6 = 600;

Creating six different variables is a bit dirty and not a good idea. What if we wanted to store a million entries? Are we supposed to create a million different variables? 😢 Isn't this bad coding?

Arrays to the rescue 🤩

Instead, we store the million items in an array sequentially in an int[] array. This can be achieved easily by following the declaration and initialization with values.

int[] array = {100, 200, 300, 400, 500, 600};

Arrays are used for efficient data storage, quick access, and optimized memory usage.

Isn't the array beautiful? 😻