Mini course in PHP (Part 10) - ARRAY ()

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http://br.php.net/manual/pt_BR/book.array.php

Hello, Today in class we'll look at array (). Array is a type of variable, remember the lesson when we saw two types of is a type of variable position is, or is a variable that can hold more than one value. For example, you can have an array that stores color, or an array that holds day of the week, or an array that stores the data of a person. So would a variable called $ person that contain the information: name, address, e-mail, phone, etc ...

Not to complicate matters, I'll show an example of array of fruit ok?

$ Fruits = array ("Banana", "Apples", "Pineapple", "Strawberry");

Got it? The variable $ fruit contains multiple values.

An array is sorted by indices, ie, to access the first position of the array $ fruit, we must inform the index: $ fruits [0].
By default, an array ALWAYS starts at index 0 (zero).
So if I want to print on the screen at the second position of the array, I do it:

In PHP, you can define an array of various forms, see below the statement that our sample array.

In the example above, see I'm explaining the array index, I could use one word instead of numbers ok? EX: $ fruits = array ("first" => "Banana", "second" => "Apple");

Another way is to declare the array:

$ Fruits [] = "Banana"
$ Fruits [] = "Apple"
$ Fruits [] = "Pineapple"
$ Fruits [] = "Strawberry"

Doing this way, each line PHP places the value at the end of the array, as it were to do so:

$ Fruits [0] = "Banana"
$ Fruits [1] = "Apple"
$ Fruits [2] = "Pineapple"
$ Fruits [3] = "Strawberry"

Ok, now let's make another array by placing some data ... Let's make an array with data from a person. I'll do it in the editor to comment on the power lines ... See image below:

Explanation of code:

Line 2: Statement of the variable is an array. This is to ensure that no errors occur when running the script, because on some servers there is a directive in the configuration of PHP that this array would not declare an alert appears on the screen .. but the script would run.
Line 3: We create a position in the array called 'name'.
Line 4: We created a position in the array called 'email'.
Line 5: We build a position in the array called 'city'.
Line 6: We created a position in the array called 'blog'.

Line 8 to 11 have it print on the screen the values ​​that were stored in the array.

But the reason to learn to work with arrays?

Simple, imagine that this is a page with details of registered users in the database ... where we declare the array $ person would be the part where we would query the database, which would return an array with the data of the selected user. Regardless of the person selected would not change anything until the line 8 to line 11. For each index, would be filled with data from the database.

Running this script, we get the following output:

If you look at the reference spent it at the beginning of the post, you will see many functions for working with array. I'll show you some very useful functions.

count (): You pass an array as a parameter and it returns how many indexes this array has (its size). Ex:

sort () / rsort (): Sort the array

sort ($ person) / / sorts an array in ascending order

rsort ($ person) / / sorts an array in increasing order DE

I passed the link, has all the functions available to work with the array. Come and take a look.

Why's it! Hope this helps .. any questions please leave a comment.