String Manipulation

Quick reference

• 00:04 In this video I want to talk about string manipulation.
• 00:07 And we've used strings a whole bunch throughout this course, it's just,
• 00:12 puts Hello World, this is a string,
• 00:14 all the stuff inside of the quotation marks is a string.
• 00:17 Now strictly speaking, a string, is a ruby class, right?
• 00:21 And inside that class,
• 00:22 there's lots of methods that you can use to do stringy type things.
• 00:27 And you can manipulate strings with those methods, and
• 00:29 we're going to look at some of those methods in this video.
• 00:32 We haven't really talked about methods, and classes, and things like that.
• 00:35 So at this point it might be a little bit over your head, but
• 00:37 don't worry about it it's basically just something we can do to our string, right?
• 00:41 So let's create a little program, let's go print, enter your name, and then say,
• 00:48 name = gets, let's chomp this thing, you're always going to want to chomp your gets.
• 00:53 And then let's say puts "Hello",
• 00:57 let's do our interpolation, hashtag and our curly braces and name.
• 01:02 I like to put spaces, you don't have to,
• 01:04 you could do it like this, but I find it's easier to read if you do it like that.
• 01:08 So we save this.
• 01:10 If we run this program, Enter your name:, John, Hello, John.
• 01:14 So we've seen this before, no big deal.
• 01:16 Now let's say we want to mess around with our string, we want to manipulate it.
• 01:19 Well, we can do all kinds of cool stuff,
• 01:21 let's say we want the output to be in lowercase.
• 01:24 I could just type in .downcase, save this, and
• 01:28 now if we run it again, enter your name: John.
• 01:31 Notice that my name is uppercase J-o-h-n, but when it outputs it,
• 01:35 it outputs it as lowercase.
• 01:37 Ruby has converted it to downcase,
• 01:39 by just slapping this .downcase on there, so that's very cool.
• 01:43 We can do upcase, if we save this and run it, if I type in john, lowercase,
• 01:49 it uppercases every single letter in my string, so that's kind of interesting.
• 01:54 So downcase, upcase, we can capitalize, if we save this,
• 01:58 what do you think this is going to do?
• 02:00 If I type in lowercase john, it capitalizes it for
• 02:03 me, it just does the first letter of the word.
• 02:05 We can do reverse.
• 02:07 This is a fun one.
• 02:09 If I type in John, it outputs nhoJ, right?
• 02:14 So if we run it again, and I type in racecar, it outputs racecar,
• 02:19 because racecar spelled backwards is racecar.
• 02:22 We can swapcase, if we run this,
• 02:27 John, I misspelled swap.
• 02:30 See, always getting errors.
• 02:32 It swapped the case.
• 02:35 Now I typed in capital J and lowercase o-h-n, it outputs lowercase j and
• 02:39 capital O-H-N, so that's kind of fun.
• 02:42 We have, this is a very useful one, length,
• 02:45 those first few were just kind of fun, this is actually very, very useful.
• 02:49 So if we save it and run it,
• 02:50 If I type in John, what do you think it's going to return?
• 02:53 4.
• 02:55 So it says, how many characters are in this string?
• 02:58 One, two, three, four.
• 03:01 So that is very useful.
• 03:03 So it doesn't matter how many, it'll tell me 48, very useful.
• 03:07 We're going to see lots of reasons to use that later on, especially with arrays and
• 03:10 things like that, loops, different things we're going to use, at.length method for.
• 03:15 So that's string manipulation.
• 03:16 Just very easy to do all kinds of weird things, and there's lots of these little
• 03:20 methods, you can look them up, string manipulation methods.
• 03:23 You could look up the string class.
• 03:25 I'll show you how to do stuff like that later on in the course, to learn about
• 03:28 these different fun little things you can do with strings, and other things as well.
• 03:31 But, that's pretty much it, we are done now with the basics of Ruby.
• 03:34 In the next section, we're going to move into intermediate Ruby and
• 03:37 we're going to look at arrays.

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