Welcome to the first lesson of this course! In this lesson, we’ll explore the fundamentals of string manipulation, focusing on scenarios where we avoid using built-in string methods. Working with individual characters in a string is an essential skill for developers.

While Ruby provides many methods for handling strings, developing a deeper understanding of how these methods work under the hood is invaluable. This knowledge strengthens your command of the language and prepares you to tackle scenarios where built-in methods aren’t available or where creating custom solutions is more efficient.

A string can be thought of as an array of characters, each accessible through its index. This array-like structure allows us to manipulate each character individually.

For example, let’s examine a common operation, such as reversing a string. To reverse a string manually, start from the last character (at an index of string.length - 1), and move towards the beginning, adding each character to a new string in reverse order. This can be done using a while loop.

Here’s how it might look:

Ruby
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1# Reversing a string manually
2original_string = "hello"
3reversed_string = ""
4i = original_string.length - 1
5
6while i >= 0
7  reversed_string << original_string[i]
8  i -= 1
9end
10
11puts reversed_string  # Output: "olleh"

This approach demonstrates how to manually iterate over a string and build a new one, an essential skill for mastering string manipulation.

Take time to absorb this concept, as it forms the foundation for more advanced string manipulation tasks.

When you’re ready, we’ll continue with hands-on exercises to deepen your understanding. Remember, our goal is not only to learn specific algorithms but also to develop the skills to systematically approach and solve problems—an essential trait for any programmer. So, let’s get coding and put these ideas into practice!