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Now that we have our errors showing
we're ready to get started actually

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addressing those errors.

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Many languages throw an exception

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whenever there is any sort
of problem with the code.

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These languages are what I
would call exception heavy.

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PHP is an exception light language.

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In most cases PHP will
output an error instead.

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Like most things in PHP, you do have
quite a bit of control over which things

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cause exceptions and
other advanced options handling errors.

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Check out the teacher’s notes for
more information.

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Errors can be output to the screen,
local disk or both.

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PHP can also choose which error severities
it will report and which it will ignore.

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The most common errors are E_NOTICE,
E_WARNING, and E_ERROR.

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After throwing a notice or a warning,
PHP will keep executing the script.

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E_ERROR or fatal errors on the other hand
halt the script in an unrecoverable way.

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It can be tempting to ignore notices or

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warnings since they don't really
stop things from working.

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But catching and fixing those things
from the start is much better practice.

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In the long run,
it's better to do things properly.

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For example,
if a feature is marked as deprecated,

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you probably wanna know about
it before it's removed.

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Otherwise, an upgrade
becomes much harder later on.

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Let's take a look at errors4.

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This file is completely
full of broken stuff.

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On line 3 we can see the error
reporting function being used.

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This function is how we control which
severity or errors will be reported.

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And this code specifically requests
that only E_ERROR, E_WARNING and

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E_PARSE are reported.

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An error being reported means
it can go into a log file.

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And maybe be displayed down
the screen depending on the settings.

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We can see in line 5 that
the display errors are turned on.

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So if we preview this script in a browser,

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we'll be able to see our errors because
we have display errors turned on.

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Here we see int(5), so
some code seems to be working.

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And we see some errors but
they're all jammed up on the same line.

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This is because it's not
outputting errors as html.

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It's outputting them with just text.

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So let's go back and
turn on html formatting.

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Much better.

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Now what's really strange is that I
know from the code that I've written

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that there should be four errors because
I intentionally broke a lot of stuff.

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Let's take a look at our code and
see what could be wrong.

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The first thing you might notice is that 5
is being added to the variable called nope

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and nowhere in this code
is nope being defined.

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That should throw a notice but
we aren't seeing one.

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This is because we have not
requested PHP to report notices.

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And as such,

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an uninitialized variable will be
treated as null without any complaints.

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5 plus null is 5, kinda.

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But it's not great to have this
sort of code in our application.

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We don't want undefined variables
floating around without any errors.

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Some developers pick and
choose specific error levels like this.

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But that means that sometimes
something might be forgotten.

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It also means that newly added error
severities like E_DEPRECATED and

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E_USERDEPRECATED would be missed.

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Picking specific error levels unless
you really know what you're doing

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is dangerous.

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The general advice of many is to
turn the error reporting level up

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as high as you can using E_ALL.

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That's really easy to change.

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You just remove all these specific
levels and change it to E_ALL.

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Now we can save that and
preview it in the browser.

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Great.

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These are the four errors I'm expecting.

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You can see that there is a notice
of an undefined variable, nope.

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It outputs 5 because it
will still do the math.

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It will just warn you about it.

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Next we see a warning, creating a default
object from an empty value on line 15.

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Next, we have a non static method, foobar,
should be called statically on line 22.

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And finally, a fatal error,
a call to an undefined method, foo, $nope.

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Let's see if we can fix these errors.

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So first, $nope equals 0.

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That should fix that notice.

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Then we wanna define our object.

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We'll set this to the standard class.

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Public function bar.

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This needs to be a static
function to fix that error.

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And then finally,
to get rid of the final fatal error,

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we need to make another
static function called $nope.

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Let's see if this has worked.

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Perfect.

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The impossible happened.

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We got to the end of the file because we
fixed all the errors thanks to reporting.

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One thing to remember
is that in production

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you never want your end user to see
PHP system errors on the screen.

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Displaying error messages to
your site visitors can disclose

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important information about your site's
setup and cause a huge security risk.

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On production, you want to have
display errors turned off.

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Next, let's talk about logging.