- Indexed Arrays 5:13
- Adding Array Elements 5:08
- List Quiz 5 questions
- Removing Array Elements 4:50
- Editing Array Elements 1:36
- Modifying Arrays 3 objectives
- Associative Arrays 3:48
- Associative Quiz 5 questions
- Mixing Data Types in Arrays 6:07
- Multidimensional Arrays 6:14
- Multidimensional Arrays 3 objectives
- Sorting Arrays 6:16
- Mixing and Sorting 5 questions
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Indexed Arrays
5:13An array is a compound variable type meaning it can contain more than one value. We'll start with a basic indexed array, which can be used as a list of items: shopping list, days of the week, the top ten scores in a game, or a todo list.
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An array is a compound variable type,
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meaning it can contain
more than one value.
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An array can be a list of
items such as a shopping list.
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It's still one variable just like all
your shopping items are in one list, but
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it can hold multiple values.
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Any time you want to store a list
of items like the days of the week,
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the top ten scores in a game or
to do list arrays are a great choice.
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Arrays are one of the most flexible and
useful ways to store information and
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PHP provides several different ways to
create and use arrays including something
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called an associative array, and a nested
array called a multi-dimensional array.
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But let's start with a basic array.
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A simple list of values.
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Let's create a new file
named indexed arrays.
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Open and close the PHP tags,
and we're ready to get started.
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We name our array variable
just like any other variable,
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a dollar sign followed by an underscore or
letter and
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then any combination of letters,
numbers, or underscores.
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Let's call this array learn and
use the assignment operator.
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Next we use the keyword array.
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And then within parentheses, we add our
list of values separated by commas.
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Conditionals, arrays and loops.
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To check out what our array looks like, we
can use the ever useful var dump function.
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And let's run our script.
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php indexed_arrays.php.
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This tells us quite a bit of
information about the array.
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First off, we see that the size equals 3,
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because there are 3 items,
or elements, in the array.
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Then we see a separate line for
each element.
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First we see the numbers one through
two followed by equal greater than.
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The equal or greater than sequence
is referred to as a double arrow.
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This double arrow represents
the relationship between the key and
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its value.
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Each array element requires a key.
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PHP automatically assigns
a numerical key by
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incrementing the largest
previously used integer key.
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By default, arrays are zero indexed,
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meaning the first value is zero
then one then two and so on.
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You'll see in a later video that
you can specify your own key and
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they don't always have to be numeric.
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The var dump shows us that our
first element has a key of zero and
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then describes the value.
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The value is of the type string,
the string it contains is Conditionals.
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And the length of characters is 18,
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each additional element is
described on its own line.
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If I want to access the second value
Arrays, I would use its key. We echo,
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the variable name, learn, followed
by the key within square brackets.
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For the second element,
I would use the key of one.
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Let's run the script again.
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Now we see after our var dump,
that we display the value arrays.
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We've looked at the array
using the var dump function,
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as well as accessed a single
value by specifying a key.
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I want to point out that you can't
just display the array directly.
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Let's test that out.
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echo learn.
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Now when I run my script, I see an error.
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There's a notice about
an array to string conversion.
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This is because arrays
store more complex data and
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PHP doesn't know how to format that data.
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So if we want to display the array
values we have to tell PHP
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how we want them formatted.
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PHP gives us a function called, implode,
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that allows us to join array elements
together into a single string.
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We can then separate
the items in this new string
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using another string of our choosing.
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This separator string can be anything
we want, even multiple HTML tags.
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Let's comment out these display lines.
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Then we’ll add echo implode and
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our separator which will
be a newline character.
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Then we pass in the array learn.
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Now let's run our script.
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We see a list of array element values.
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