PHP-and-MySQL/C2/Arrays/English-timed

From Script | Spoken-Tutorial
Revision as of 20:55, 15 December 2018 by Sandhya.np14 (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search
Time Narration
00:00 Hello and welcome to the tutorial on Arrays.
00:03 Arrays allow the user to store more than one piece of data inside a variable.
00:08 For example, the variable $days would be called as an array.
00:12 Inside a pair of parentheses, we're going to have more than one value.
00:17 So, I'll pick 5 values for this and have every day of the week inside each of these.
00:23 I'll have Monday, Tuesday, Wednesday, Thursday and Friday - just 5 days of the week, that saves us.
00:39 Say for example, day one ($day1) is Monday, day two is Tuesday and so on.
00:49 Hope you get the picture. This is a much easier and more efficient way of calling a variable with more than one piece of data inside it.
00:59 Please note that these can also be numbers or whatever data that you decide, you require inside them.
01:07 Now, to echo out our array, I'm going to say echo $days.
01:12 Now, you find that this doesn't work.
01:16 This happens when we open up our page.
01:20 We just get "Array" echoed out.
01:22 Now, "Array" is not anywhere inside here.
01:24 So, what PHP has done is, echoed out the fact that what we have is an array.
01:32 Now, to call a specific element inside an array, you might want to call it element, in some places they call it id tags or elements of an array.
01:41 We're going to use square brackets and we'll call the position of the element inside the array.
01:45 So, you may think this is one, two, three, four, five.
01:50 However, because of the numbering system- the standard numbering system, we are starting with zero, one, two, three and four.
01:58 So, for example, if I wanted to echo out Monday that would be zero; so, you put zero in that and you have Monday echoed out.
02:09 The same with one would be Tuesday and four which is the last element of the array would be Friday.
02:18 Okay. So, we're going to go ahead and I'm going to show you how to assign values in a different way into an array.
02:26 Now, let me start from the beginning of what I want to say.
02:32 I'm going to create an array but I'm going to create it specifically.
02:39 So, $days zero equals Monday, days one equals Tuesday.
02:53 Now, you may think - what's the point of this? I mean, what I'm doing here essentially is creating what I said earlier would be a bit of a hassle.
03:04 I mean I could say day 1 equals, you know and day 2 equals and you could do it like that.
03:15 However, what we're still doing here is putting into an array.
03:19 So, it may still contain the same structure but we're assigning it in a different way.
03:25 So, you can do it like that. I always prefer to do it like this.
03:33 I find this much cleaner, much simpler and just to let you know - you can bring this down like this.
03:45 However, if you prefer to view it, I mean if I save this now, refresh, nothing is changed.
03:54 There are no errors, we still get the same structure, we've just moved it down on lines.
04:01 There's the line terminator at the end of your function and not at the end of every line; so, don't get confused with that.
04:11 Okay. So, let's now go back to this.
04:15 So, that's the basic array and how to create values for it in two different ways and how to call values for it.
04:23 So, for example if I was saying echo "Today is" $days and then I can say zero.
04:34 Now, you can see already that I've highlighted this in context - I've highlighted that in green.
04:41 Now, if you refresh this, you'll see "This is Monday".
04:44 Now don't get confused, I do recommend you to use contexts.
04:48 However, this isn't the standard way that contact recognizes the coding.
04:53 What it would look better is - you'll see that when we write it down here, we could say echo $days and zero; you can see how that's in red to show an integer, a number.
05:09 The way it would like you to write is like that and we can see, that's fine.
05:16 But you can incorporate an array into your string in order to echo it out.
05:23 Anyway, I'm going to go on to associative arrays where we're going to assign id tags in a way where we hold a value for each sort of identity.
05:36 If you don't follow, then this is the way I'm going to create it.
05:46 I'm going to say $ages equals array(); now inside, I'm going to say "Alex".
06:03 Now, instead of going on and saying "Billy" and then "Kyle" which are the three names I'm going to use, I'm going to say nineteen, fourteen and eighteen.
06:20 Basically using equals and a greater than sign (=>).
06:24 Now, what this has done is instead of our array elements as in this being called by zero, this being called by one, this being called by two.
06:34 This is now called as "Alex", this is called as "Billy" and this is called as "Kyle" but their values are fourteen, nineteen and eighteen.
06:45 So, really, it would be the same as writing that. Let's get rid of that and calling this as zero, one and two.
06:55 And to make it a bit more friendly and a bit easier to remember, a bit easier to call, we can now say: echo out $ages "Alex" like that.
07:09 So, this will echo out nineteen as we refresh and see there - nineteen. The same if you do it with 'Billy' and the same with 'Kyle'.
07:24 So, when you're half way through a program and instead of saying aah!! I'll have to go back to the top and count along each row and say "Is this zero, one, two or three, I can't remember?"
07:38 This is much easier to do. Another useful way of doing this is, if I was to say array one is equal to 'Alex' and then two is equal to 'Billy' ,
07:50 we are not starting at zero and then one. We're starting at one and two so that we find that is easier to remember.
08:00 Now, we can now say echo $ages one, that comes out as "Alex".
08:08 We're not using zero for that, it's a lot more user friendly for you to program than to say- zero, one, two.
08:17 Try it out - work around it - see what's easiest for you.
08:21 But, I mean this to me is quite pointless because I'm in the mood of using zero, one, two.
08:28 But if you want to use it like I have before or like this or assign a string value to any data type then that's the way to do it.
08:37 Okay, that's the basics of arrays. I have another tutorial on multidimensional arrays.
08:44 Its a separate tutorial. Please watch it.
08:47 That's all in this tutorial. Thanks for watching. This is Arvind, dubbing for the Spoken Tutorial project. Bye.

Contributors and Content Editors

Minal, PoojaMoolya, Pratik kamble, Sandhya.np14