Strings – Character Arrays

Before You Apply

First observe the behavior in Explore mode, then switch to Apply to test each operation with intent.

Core Idea

A string is a sequence of characters. In most languages, strings are implemented as arrays of characters, either mutable or immutable depending on the language.

Observe This First

Sequence of characters: 'H', 'e', 'l', 'l', 'o'

Then Apply

Reverse: Swap characters from both ends → O(n)

Strings – Character Arrays Lab

Click characters to inspect index and character value.

Build Your Own String

Use next/previous for backward and forward explanation, or press play for continuous animation.

Current string: Claviro

Ready|Waiting for a string operation

Time: Depends on operation|Space: O(1) auxiliary

Current

Comparing

Updated

Active

Pseudocode

1read char at index

2overwrite one character

3append character to the end

4visit characters from left to right

Strings act like indexed character arrays for access and traversal.

Explanation

Explore mode: strings behave like indexed character arrays.

Understanding the Observation

What did you observe?

Indexed like arrays: Each character has a position

Why did this happen?

Sequence of characters: 'H', 'e', 'l', 'l', 'o'

Apply with purpose

In Apply mode, test one operation and explain its complexity before running the next.

Predict next

Before clicking run, predict the next index/pointer movement and then verify it.