String Objects – Substring

search string

In a continuation of my last post, I want to cover another useful method for string objects…indexOf(). I know indexOf() sounds cryptic, but it is fairly straight forward. It simply allows you to search to see if a string contains a substring.

A substring is a portion of a string. For example, if I have the following string…”Hello World”, then a substring could be “World”. So it is a portion of the entire string. Let’s see an example…

var myString = "This is an example of using the indexOf method to search a string for a substring.";
var stringLocation = myString.indexOf("example");
console.log(stringLocation);

If you run the aforementioned code, the value of the variable, stringLocation, would be 11. Why 11? Well, indexOf() returns the beginning location in the string where the item for which you are searching begins. Counting is zero-based (begins at zero). So if we count the characters of the string…

T – 0 | h – 1 | i – 2 | s – 3 | [space] – 4 | i – 5 | s – 6 | [space] – 7 | a – 8 | n – 9 | [space] – 10 | e – 11

Now that you have the starting location for the substring, you can then perform some string manipulation, but more on that in future posts.

Now, what happens if the substring does not exist? Then the indexOf() method returns -1.

var myString = "This is an example of using the indexOf method to search a string for a substring.";
var stringLocation = myString.indexOf("not found");
console.log(stringLocation);

In this example, the stringLocation variable would be -1. You could use this in IF statements, etc.

Happy coding!

Clay Hess

More To Explore

Code

Exploring the Broadcast Channel API: Inter-Tab Communication

Intercommunication between different contexts (like tabs, iframes or workers) of the same origin has often been a challenge. With the Broadcast Channel API, developers now have a powerful tool to easily communicate between browsing contexts. In this blog post, we’ll dive deep into the capabilities of the Broadcast Channel API, exploring its features, use cases, and how it can be effectively implemented in your projects.

computer, laptop, work place-2982270.jpg
Code

Unlocking Wireless Communication: A Dive into the Bluetooth API

Wireless communication has become an integral part of our daily lives, and Bluetooth technology is at the forefront of this revolution, enabling devices to exchange data over short distances and creating a world more interconnected than ever before. At the heart of this technology lies the Bluetooth Application Programming Interface (API), a powerful tool for developers looking to harness the capabilities of Bluetooth in their applications. In this blog post, we’ll explore what the Bluetooth API is, how it works, and the possibilities it opens up for innovation in wireless communication.

Share This Post

small_c_popup.png

Need help?

Let's have a chat...


Login

Jump Back In!

Here at Webolution Designs, we love to learn. This includes sharing things we have learned with you. 

Register

Begin Your Learning Journey Today!

Come back inside to continue your learning journey.