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An operator is something that takes 1 or
more values and yields another value.

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I've shown you several
different operators so far.

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The assignment operator uses the equal
sign to put a value into a variable.

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The arithmetic operators let you add,
subtract, divide, and multiply numbers.

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And the concatenation operators
let you create a new string

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by combining several strings together.

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Next we'll be looking at
comparison operators for equality.

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Comparison operators do
exactly what they sound like.

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They allow us to compare values and
yield the result.

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There are quite a few
comparison operators, and

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we'll cover them all in a later course.

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I have included more information
in the teacher's notes,

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if you want to learn more now.

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For this course, we'll be looking
at equal and identical comparisons.

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Equal compares only the value, while
identical compares the value and the type.

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We've looked at the number of different
variable types in PHP including

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integers, floats, strings and booleans.

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PHP is called a weakly or
loosely typed language.

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This means that, generally, you don't
need to specify the type you'll be using.

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PHP will automatically assign the type for

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you based on the value
inside the variable.

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This also means that PHP will attempt

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to juggle the types to work within
the situation in which they're being used.

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We saw this when working
with number variables.

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When you were using the plus
sign to add two variables

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PHP assumes that those values
should be evaluated as numbers.

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Type juggling can be
helpful when accepting data

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from sources beyond your control
like user data from a web form.

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Values submitted from an online
form are collected as a string, but

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they can be used in a calculation
because of Type Juggling.

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Let's comment out

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these output lines.

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Then let's start with something simple.

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We'll add var_dump(1 + "2").

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Now let's run our script.

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Since we're using an addition operator,

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when we run our program PHP juggles
the string 2 to an integer and

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adds 1 + 2, which gives us
the integer 3 as the result.

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So now let's take a look
at the comparison operator.

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We'll start by creating two variables,

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a = 10 and b = '10'.

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Then we can compare these
variables as equal and

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use our var_dump to display the results.

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When we run the script,

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we see that the evaluation is true
because both values equal 10.

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If we want to compare if these
variables are identical, meaning that

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the value is the same and also the type
is the same we use the triple equals.

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When we run the script now,
we see that the evaluation is false,

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because a and b are not the same type.

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We can also use these to compare strings.

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We'll var_dump again, and

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then we'll compare string_one

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to be equal to learning to display

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Hello Alena to the screen.

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Let's uncomment this line
to echo out our string, so

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we can see what that looks like.

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Great.

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Well, let's also comment
about these //var_dumps.

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There we go.

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That should make our output
a little easier to read.

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Our result of string_one
isn't exactly the same,

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because we have I am in front,
and we also have a new line.

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So the var_dump evaluates
to the boolean false.

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Let's update the string_one value and
remove the new line and

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prepend string using our comments.

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Not this or this.

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Now let's run our script again.

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Great, now our var_dump evaluates to true.

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Even though string_one uses the name
variable, the values are the same.