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All right guys.

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Let's get back to learning about a few more things that we can do with strings.

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You saw in the last lesson that if we wanted to print things on individual

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lines, then we actually had to write them a few times, right?

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We had to write print, um,

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on three lines if we wanted it to be printed one, two, three,

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like so. Now in this lesson I want to show you a method where we can do the same

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thing, but by using a single print method.

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So saving ourselves a few characters.

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So the way that we would create a new line is by writing a backslash and the N

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character.

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And now if I go ahead and write hello world again afterward and I hit run,

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or you can always use the shortcut, which is command + enter on Mac or control +

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enter on Windows.

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And you can see that once that line of code has been executed,

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I've got hello world printed on two separate lines,

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separated by this pink \n and character,

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which gets replaced by a new line.

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So go ahead and give that a go and see if you can create another one.

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Remember though,

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it's a backslash and not a forward slash but the syntax highlighting should help

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you. All right,

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we can simply just add another \n and remember that unless you want a

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space to appear right before where your hello world appears,

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you actually don't want any gaps between each of these lines.

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There we go. We've got the same result as before,

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but now using only a single print statement and creating some new lines with the

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\n.

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Now one of the other things that we can do with strings is we can concatenate

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them.

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What this means is we combine different strings so that they will be added to

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the end of another string. Here's an example.

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Let's say that we had the word hello and I wanted to add my name to the end of

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this word to make it a single string. Well,

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I can combine two strings by simply using a plus sign. So I can write "Hello" 

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+ "Angela". Now here's a question. When this runs,

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what do you think it will look like? Do you think it'll write Hello 

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Angela or hello Angela, all in one word? Let's see what happens.

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You can see that these two strings have now been combined into one and there's

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no space in between because we don't have a space character anywhere in here.

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Pause the video and see if you can add a space in between.

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Alright,

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so there are two ways that you can do this or maybe three actually. You could add a

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space to the end of hello, you could add a space to

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the beginning of Angela or you can actually continue using string concatenation

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by simply adding another string in between these two

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and this one is just a space. So now when I run my code,

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you can see the space gets inserted and this long thing gets combined into a

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single string that looks like this

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once this bit of the code gets executed.

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If we think of strings as a string of connected characters,

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then string concatenation is simply taking those separate strings of characters

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and merging them into one. Now,

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this is a good point to mention that in Python programming spaces are really,

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really important.

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And what I mean by this is not so much the spaces that are inside strings like

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this one, but the spaces that you add in your code.

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So here, my print statement, if I hit the backspace,

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you can see that nothing happens. I can't go any further back.

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But if I added a space or if I added a tab using the TAB key,

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then you'll see that when I try to run my code, I actually get an error.

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And the type of error this time is not a syntax error anymore.

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It's now an indentation error.

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And it says that there's an unexpected indent at this position right at the

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beginning of the print statement. So when you're coding in Python,

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it's really important that you start off all of your code at the beginning of

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the line and that you don't accidentally have any spaces or any tabs that you've

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inserted in front of the line of code.

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And the next time you get an indentation error,

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then you'll be able to look at where that error is and hopefully you'll be able to

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either use Stack Overflow or just remember what this error message means and

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you'll be able to fix your code.

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Now this is the second error that we've come across.

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The last error was a syntax error for example,

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when we forgot to add the end double quotes.

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And this one is called a syntax error and this one is called an indentation error.

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And as I mentioned before, while you're coding,

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you are going to make lots and lots of these errors and other ones.

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This is the only sure thing that we know.

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So it's great that you're already learning about them and recognizing them.

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But how can we prevent this from happening in the first place? Well,

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paying attention while you're typing helps, but we all get tired and sometimes,

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especially when I'm coding at night, sometimes even when I look at my own name,

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it looks like it's spelled wrong and I can't figure out left and right.

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So in most cases, text editors have a lot of helpful features.

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If you go into the settings bar here and you scroll all the way to the bottom,

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you can see that there's something called Code Intelligence. And code

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intelligence is something that is going to help you auto-complete some of the

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functions like our print function here and give you some helpful information or

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hints as you type.

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So let's go ahead and change it to enabled and close down our settings pane.

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And you can see now if I, for example, forget to add my double quotes,

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then I already start to get a little red squiggly line here and a little red bit

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in the right hand side of the scroll bar.

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And if I hover over the red squiggly line,

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you can see that it gives me the error that I would get if I ran my code right

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now. And so it reminds me that, Oh yeah,

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there's maybe something about my string that's not quite right.

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And you can also just Google these error messages and see it in Stack Overflow

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to remind yourself of what the error might be relating to.

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And I can fix it without having to run my code and having it break.

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Because remember that when you're writing large programs,

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it's not just going to be one line of code.

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You can have multiple lines of code each with their own errors.

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For example, this one might be missing a double quote,

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this one might be missing a plus sign,

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this one might have the print function misspelled.

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The next one might have a indentation that's not meant to be there,

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and when you run your code like this, it'll only give you the first issue.

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Once you fix that issue,

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it'll continue to the next issue until you've fixed everything,

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and this is really painful. But with code intelligence enabled,

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every time we make an error such as an indentation error like this,

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then we'll be able to hover over it and you'll see unexpected indent.

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So we'll be able to fix that. If we forget to close off our print statement,

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then we'll get a little squiggly line next to it.

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And if we say misspelled our print statement,

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we'll also get errors telling us that undefined name or it doesn't know what

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this 'prnt' is and the syntax highlighting also changes and everything should

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all help you to avoid mistakes and write good solid code.

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So now it's time for another code challenge.

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And in this code challenge,

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I've got a whole bunch of broken code for you and your job is to debug or remove

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the bugs from the code and make the code run without any errors.

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This word debugging actually comes from a story where back in the 1980s a

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moth actually flew into one of the early computers and it got electrocuted

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unfortunately for the moth and for the programmer,

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it meant that his code wasn't performing as he would expect it to.

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So he actually had to go into the computer, pick out the moth,

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and fix the wires so that it would work again.

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Now we don't have any moths flying around in our code, thankfully,

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but what we do have to do is we have to pick out the errors so that our code will

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run in the way that we expect it to without any errors.

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So head over to the next lesson and try out your first debugging exercise.