Preview
Video Player
00:00
00:00
Integers
5:19Integers are whole numbers, such as one through nine or negative one through negative nine. Any of these are considered integers because they aren't numbers that include decimal, or floating point, values. We'll be setting, retrieving, preforming operations and functions and displaying these values!
The first type of variable we're
going to look at is an integer.
0:00
Integers are whole numbers,
such as one through nine, or
0:03
negative one through negative nine.
0:07
Any of these are considered integers
because they aren't numbers that include
0:09
decimals or floating point values.
0:14
So let's create a couple of integers and
see how they work.
0:17
Let's create a new file named numbers.php.
0:21
Remember, we start a PHP block using
the opening and closing php tags.
0:29
Now we can create some variables.
0:35
The names don't really matter, but
I want to keep it readable, so
0:38
I'll name the first one num_one.
0:41
To store information in this variable,
0:45
we use a single equal sign, followed
by the value that we want to store.
0:47
In this case,
I'm going to set it equal to one.
0:52
I then end this statement in
this line with a semicolon.
0:56
If you notice, I'm not putting
quotes around the number one.
1:00
If I were to put quotes around the one,
1:04
PHP would treat this value as a string,
not an integer.
1:05
I'll show you the difference between
strings and integers here in a minute.
1:10
But let's create a few more,
num_two equals two,
1:13
and num_three will equal three.
1:19
So now we have three variables,
num_one, num_two, and num_three.
1:25
Let's display these variables
using the echo command.
1:28
We’ll echo num_one.
1:31
Then we can run this script.
1:37
We see that it displays the value,
which is one.
1:43
Our variable is just a placeholder for
the value.
1:46
It's just a one.
1:49
So what about if we were to just echo,
say, one, and not the variable?
1:51
Let's also put a one within quotes.
1:56
Now let's run our script again.
2:00
Now we have three ones, and
they all look exactly the same.
2:03
So how do we know that something is
an integer or something is a string?
2:06
PHP includes some functions that we can
use to perform many different tasks,
2:10
such as looking at
the details of a variable.
2:15
A function is simply a group of code
that performs a function or task.
2:19
We'll learn about writing our own
functions in a later course, but
2:24
we can start using them now.
2:27
The first function we'll use is a very
handy little function, var_dump.
2:30
The var_dump function accepts
data within parentheses and
2:36
dumps the details about that data.
2:39
Instead of echo, let's use var_dump.
2:42
We then surround the data we
want to use in parentheses.
2:46
Let's use the var_dump on all three lines.
2:51
Now let's run our script again.
3:03
So you'll notice here,
the first two types are int, or integer,
3:07
with the value of one without quotes.
3:11
And the third type is a string with
the value of one within quotes.
3:14
So now we can tell that there
are actually two different types.
3:19
At this point, it's not a concern that
these two values are different types,
3:23
since we're getting
the same output either way.
3:28
However, as you'll learn later, sometimes,
like when performing a math calculation,
3:31
the type of information stored
in a variable really matters.
3:35
So it's good to know that we can test and
3:39
find out whether our variable
contains an integer or a string.
3:41
There are other functions
you can use with variables.
3:45
So check the teacher's notes for
more details.
3:48
Let's duplicate the first var_dump line,
and do some math calculations.
3:51
After num_one, I'm going to use
an operator that you see all the time,
3:58
the plus sign.
4:02
Then I'm going to type num_two.
4:04
Now let's run the script again.
4:09
We see that the last result is also
an integer with a value of three.
4:13
One plus two equals three, awesome.
4:17
By using the plus operator, or
4:21
sum operator,
we're able to add two numbers together.
4:23
The numbers are integers, and
they're stored in variables,
4:27
so we can change or
retrieve them however we'd like.
4:31
Let's do a little bit more here,
and say minus.
4:34
And now we'll type num_three.
4:41
We save the file and run the script again.
4:44
That brings us to zero.
4:48
One plus two minus three equals zero.
4:50
Great job storing, retrieving, and
manipulating your first set of data.
4:55
That should give you a good understanding
of what an integer is and how to use one.
5:00
Not all numbers are integers.
5:05
Oftentimes, you'll need a floating
point value, such as 2.25, to represent
5:07
a dollar amount, or other decimal number. Enter our next variable type, floats.
5:13