PHP with MySQL Essential Training
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Array functions


PHP with MySQL Essential Training

with Kevin Skoglund

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Video: Array functions

In this movie I want us to talk about array functions. An there are a lot of functions for working with arrays, because arrays are super useful an we're going to use them in a lot a different context. And there's lots a things that we might want to do with them, and ways we want to manipulate that information. So we're going to look at a few of the most common ones, and then I'm going to show you how you can look up the rest of them. Let's start with let's create ourselves a new file for this. And let's make our basic .HTML file, Save As. We'll call this array_functions.php. Here we go, ten box/g, array functions.
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  1. 4m 8s
    1. Welcome
      1m 0s
    2. Using the exercise files
      3m 8s
  2. 15m 6s
    1. What is PHP?
      3m 52s
    2. The history of PHP
      2m 51s
    3. Why choose PHP?
      4m 10s
    4. Installation overview
      4m 13s
  3. 1h 3m
    1. Overview
      2m 33s
    2. Working with Apache Web Server
      6m 56s
    3. Changing the document root
      7m 24s
    4. Installing to Yosemite NEW
      8m 13s
    5. Enabling PHP
      6m 16s
    6. Upgrading PHP
      3m 30s
    7. Configuring PHP
      10m 3s
    8. Installing MySQL
      5m 46s
    9. Configuring MySQL
      7m 24s
    10. Text editor
      5m 1s
  4. 31m 25s
    1. Overview
      3m 27s
    2. Installing WampServer
      5m 46s
    3. Finding the document root
      2m 24s
    4. Configuring PHP
      8m 12s
    5. Configuring MySQL
      5m 45s
    6. Text editor
      5m 51s
  5. 19m 12s
    1. Embedding PHP code on a page
      6m 43s
    2. Outputting dynamic text
      5m 55s
    3. The operational trail
      2m 27s
    4. Inserting code comments
      4m 7s
  6. 1h 18m
    1. Variables
      7m 50s
    2. Strings
      4m 38s
    3. String functions
      8m 54s
    4. Numbers part one: Integers
      6m 27s
    5. Numbers part two: Floating points
      5m 25s
    6. Arrays
      10m 0s
    7. Associative arrays
      6m 37s
    8. Array functions
      6m 33s
    9. Booleans
      3m 50s
    10. NULL and empty
      5m 15s
    11. Type juggling and casting
      8m 27s
    12. Constants
      4m 43s
  7. 27m 37s
    1. If statements
      6m 0s
    2. Else and elseif statements
      4m 16s
    3. Logical operators
      7m 30s
    4. Switch statements
      9m 51s
  8. 42m 15s
    1. While loops
      8m 41s
    2. For loops
      5m 59s
    3. Foreach loops
      8m 16s
    4. Continue
      8m 28s
    5. Break
      4m 8s
    6. Understanding array pointers
      6m 43s
  9. 37m 25s
    1. Defining functions
      8m 25s
    2. Function arguments
      5m 32s
    3. Returning values from a function
      7m 33s
    4. Multiple return values
      4m 53s
    5. Scope and global variables
      6m 2s
    6. Setting default argument values
      5m 0s
  10. 20m 18s
    1. Common problems
      3m 47s
    2. Warnings and errors
      8m 36s
    3. Debugging and troubleshooting
      7m 55s
  11. 57m 57s
    1. Links and URLs
      5m 33s
    2. Using GET values
      5m 35s
    3. Encoding GET values
      8m 41s
    4. Encoding for HTML
      9m 26s
    5. Including and requiring files
      7m 40s
    6. Modifying headers
      6m 45s
    7. Page redirection
      6m 43s
    8. Output buffering
      7m 34s
  12. 1h 3m
    1. Building forms
      7m 28s
    2. Detecting form submissions
      5m 59s
    3. Single-page form processing
      7m 57s
    4. Validating form values
      10m 40s
    5. Problems with validation logic
      9m 54s
    6. Displaying validation errors
      7m 23s
    7. Custom validation functions
      6m 28s
    8. Single-page form with validations
      7m 25s
  13. 28m 5s
    1. Working with cookies
      2m 49s
    2. Setting cookie values
      5m 55s
    3. Reading cookie values
      6m 1s
    4. Unsetting cookie values
      4m 51s
    5. Working with sessions
      8m 29s
  14. 48m 39s
    1. MySQL introduction
      6m 43s
    2. Creating a database
      7m 41s
    3. Creating a database table
      7m 42s
    4. CRUD in MySQL
      5m 48s
    5. Populating a MySQL database
      7m 32s
    6. Relational database tables
      6m 40s
    7. Populating the relational table
      6m 33s
  15. 56m 4s
    1. Database APIs in PHP
      4m 51s
    2. Connecting to MySQL with PHP
      7m 45s
    3. Retrieving data from MySQL
      8m 47s
    4. Working with retrieved data
      6m 12s
    5. Creating records with PHP
      6m 58s
    6. Updating and deleting records with PHP
      9m 6s
    7. SQL injection
      3m 5s
    8. Escaping strings for MySQL
      6m 45s
    9. Introducing prepared statements
      2m 35s
  16. 35m 58s
    1. Blueprinting the application
      7m 19s
    2. Building the CMS database
      5m 14s
    3. Establishing your work area
      4m 38s
    4. Creating and styling the first page
      4m 22s
    5. Making page assets reusable
      6m 36s
    6. Connecting the application to the database
      7m 49s
  17. 32m 49s
    1. Adding pages to the navigation subjects
      5m 58s
    2. Refactoring the navigation
      6m 7s
    3. Selecting pages from the navigation
      6m 2s
    4. Highlighting the current page
      5m 26s
    5. Moving the navigation to a function
      9m 16s
  18. 1h 45m
    1. Finding a subject in the database
      9m 48s
    2. Refactoring the page selection
      10m 52s
    3. Creating a new subject form
      6m 55s
    4. Processing form values and adding subjects
      11m 20s
    5. Passing data in the session
      9m 16s
    6. Validating form values
      9m 40s
    7. Creating an edit subject form
      8m 30s
    8. Using single-page submission
      7m 44s
    9. Deleting a subject
      9m 44s
    10. Cleaning up
      10m 37s
    11. Assignment: Pages CRUD
      4m 30s
    12. Assignment results: Pages CRUD
      6m 10s
  19. 39m 26s
    1. The public appearance
      8m 52s
    2. Using a context for conditional code
      11m 37s
    3. Adding a default subject behavior
      6m 9s
    4. The public content area
      5m 51s
    5. Protecting page visibility
      6m 57s
  20. 1h 3m
    1. User authentication overview
      4m 3s
    2. Admin CRUD
      8m 41s
    3. Encrypting passwords
      7m 26s
    4. Salting passwords
      5m 42s
    5. Adding password encryption to CMS
      11m 54s
    6. New PHP password functions
      3m 13s
    7. Creating a login system
      11m 28s
    8. Checking for authorization
      5m 48s
    9. Creating a logout page
      5m 40s
  21. 2m 4s
    1. Next steps
      2m 4s

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PHP with MySQL Essential Training from
14h 24m Beginner Jun 04, 2013 Updated May 20, 2015

Viewers: in countries Watching now:

PHP is a popular, reliable programming language at the foundation of many smart, data-driven websites. This comprehensive course from Kevin Skoglund helps developers learn the basics of PHP (including variables, logical expressions, loops, and functions), understand how to connect PHP to a MySQL database, and gain experience developing a complete web application with site navigation, form validation, and a password-protected admin area. Kevin also covers the basic CRUD routines for updating a database, debugging techniques, and usable user interfaces. Along the way, he provides practical advice, offers examples of best practices, and demonstrates refactoring techniques to improve existing code.

Topics include:
  • What is PHP?
  • Installing and configuring PHP and MySQL
  • Exploring data types
  • Controlling code with logical expressions and loops
  • Using PHP's built-in functions
  • Writing custom functions
  • Building dynamic webpages
  • Working with forms and form data
  • Using cookies and sessions to store data
  • Connecting to MySQL with PHP
  • Creating and editing database records
  • Building a content management system
  • Adding user authentication
Kevin Skoglund

Array functions

In this movie I want us to talk about array functions. An there are a lot of functions for working with arrays, because arrays are super useful an we're going to use them in a lot a different context. And there's lots a things that we might want to do with them, and ways we want to manipulate that information. So we're going to look at a few of the most common ones, and then I'm going to show you how you can look up the rest of them. Let's start with let's create ourselves a new file for this. And let's make our basic .HTML file, Save As. We'll call this array_functions.php. Here we go, ten box/g, array functions.

So, to start with, I'm going to Paste in a numbers array, which is the same numbers that we were working with in the last two videos. But the difference is that I've jumbled them all around, they're not in the same order anymore. That's because one of the things that we're going to be looking at is how we can sort those numbers. Before we do that, want to look at a couple of other ones. The simpliest one of course is just that we can count those values. We can use count to tell us how many items are in the array. What's the size, what are the number of items it contains. There's max which will tell us the maximum value, and min to tell us the minimum value. That's very handy especially if we're working with max. And want to make sure that we take something that's always the maximum of several choices or the minimum of several choices.

Let's bring those up in a browser and take a look. Let's Save that and go back to Firefox, and, instead of associative arrays, we're now going to be looking at array functions. So, 6 values in there, the maximum value is 42, the minimum value is 4. As I said, we can also sort those values. Let me make this window a little bigger here. So I'm going to sort them and then right after I sort them, we'll use print_r to output it so we can see the result. So sort and then output it. And then rsort is for reverse sort, and we'll output the result of that.

Take a look at what each of those give us. So reload this page, so Sort and then Reverse sort. If you'd like you can put pre tags around those to make it easier to read, let's do that real quick, there we go. You can see that sort return them in ascending order while reverse sort return them descending order by value. Now there are rules if these aren't numbers as to how they get sorted. Obviously if you are sorting a bunch of strings, you sort them alphabetically by the first letter, then the second letter and so on.

If you were sorting an array that had a mixture of things, it would sort them for you. But the sort order might not be what you'd expect, because whether it sorts a letter before a number or a number before a letter is a little bit arbitrary. And you'd have to look that up in PHP to see which one it was going to do. So you typically wouldn't do it in that case, but it would go ahead and handle it for you. Notice one thing about sort, which is that it actually sorted the array in place. We didn't do any kind of assignment, we didn't have to say numbers equals a sorted version of that, right? It changed it in place, it's a destructive function. So, our old version, our old, unsorted version, doesn't exist anymore, right? It sorted them in place.

Another handy function is how we can turn an array, into a string. In other words, combine values together to get a string, and we can do that with implode. So what we do is we say what array we want is the second argument. The first argument is what the separator is between each of those elements. So here, I've said it's a space and an asterisk and a space. I'll save that, and you'll see what it looks like. Let's just do an echo on that so we can see it. And you'll see that it imploded it, now it's 41 star 23 star 16 star, right? It's not an array anymore, this is a string.

We could do get type on that and we would see that it was a string now. The opposite of Implode is Explode. So explode is going to take a string like num_string and every time that it finds this string, it's going to use it as a divider between the values. So every time it sees space astrik space, it's going to say alright. That's where I need to split this into a new object in the array. So we can see what it does here. Let's come back, Return, and you can see that here's the array.

It divided it back up into each of the values. It took this string, it said alright 42 is the first value. This is a separator, twenty three is the next value, this is a separator and so on. This is extremely useful when you're working with something like a comma separated list, right? So you have first name comma last name comma address comma city comma state comma zip and that sort of thing. Well you can break that up into an array by telling it to explode it, based on where the commas are. Another useful thing to be able to do, is to be able to tell whether or not something is in an array or not, does an array contain a value? So 15 in an array, echo, does the array contain the number 15 inside numbers, and it's going to return true or false.

Is 19 in the array? And it's going to return either true or false for whether 19 is inside the array numbers. So in_array is what allows us to do that, let's Save that. Try that out. So,15 in an array? Yes it is. True is represented by 1 here. 19 in an array? No, false. False is represented by having nothing there. Now, as I said, there are many, many functions for working with arrays. If you go to the website. So,, and then your language, en/ref.array.php. Here's array functions, and here's a whole long list of them. You can see, I can just scroll down the list here. There are few that I think are esspecially interesting. There is array_keys, that returns just another array of only the keys from an accosiative array.

And then there's the same thing for array values down here. Returns just the values. So, if you have a key value pairs, you can just grab all the keys out of it, or all the values out of it. Array_push is an interesting one that allows you to push an element onto the end of an array. Array_pop does the opposite. It takes an element off the end of the array. Array-shift is what you would use to put an element onto the front of an array, and array_unshift is what you would use to take it off of the beginning of an array. Array_unique will make sure that all of the items are unique in the array, it takes out any duplicates. There's array_search up here, that searches the array for a given value and returns the corresponding key if it finds it.

So it's a value search through your array. And then array_random is also nice, array_rand, underscore rand. This can take one or more random entries out of an array. So each one of those you can click through, you can look for the documentation on it, you can surf around in these. If you're working with an array, and you're not sure how to accomplish what you want, this page may provide the answers that you're looking for.

Find answers to the most frequently asked questions about PHP with MySQL Essential Training .

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Q: This course was revised on 6/4/2013. What changed?
A: The old version of this course was 6 years old and it was time for a complete revision, using PHP 5.4. (The tutorials will work with any version of PHP and covers any differences you might encounter). The author has also added updated installation instructions for Mac OS X Mountain Lion and Windows 8. The topics and end project are the same, but the code is slightly different. It also addresses frequently asked questions from the previous version.
Q: This course was updated on 5/20/2015. What changed?
A: We added one movie called "Changing the document root in Yosemite," which helps the Mac installation run more smoothly.
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