 In this lesson, we're going to look at working with characters and strings. First, let's just make sure that our kernel has loaded. As usual, I just make use of that little function. I'm just going to add 2 plus 2. And let's wait for it to get 4. Everything seems to work. So, working with characters, letters and strings. So, we're interested here in words and sentences and letters. Anything that you can write that makes sense as characters. Now, Julia can do both ASCII. That's the American Standard Code for Information Interchange and the Unicode characters. Now, remember the ASCII set of characters, they just map the integer values of 0 to 127 to a specific character. So, A, B, C, a backslash, a full stop, a space. All of those things on your keyboard, they just have an integer value. And then the Unicode set of characters, many, many more. There's about 120,000 characters from, as you can see, the 129 modern and not so modern scripts. Because really, when we talk about characters, when we talk about sentences, we talk about language and a computer has to be able to represent most of those. So, what are we going to look at? We're going to just introduce some strings so you can become comfortable with how Julia deals with them. We're going to look at substrings. We're going to look at individual characters because Julia can deal with individual characters. It's a different data type, a different type, I should say, than a full string. We're going to split and join certain strings. We're going to convert strings into integers. And we're going to look at some other conversions. We're going to find and replace characters and substrings inside of other strings because that's what we ultimately care about. We want to get some information that we can use, say, for instance, in data science out of the characters. And then lastly, something which some people love, some people hate, but certainly, certainly quite interesting, we're going to get to grips with some regular expressions or the use of regular expressions in Julia. Let's get started.