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Turning on errors within an individual
PHP file can be helpful and

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quick, especially if you don't
have access to the server, or

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you're just trying to track
down an error on one page.

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This also allows you to override
the settings in the PHP.INI file.

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We can use this to turn on, off, or
change the level of errors to display.

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The problem with using
only your own PHP file is,

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parse errors will stop PHP from
processing your code at all.

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This means,
PHP will never even see those settings.

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These shortcomings aside, sometimes this
is your best option at the time, and

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you need to change settings momentarily.

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Or for a particular file.

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Let's explore these options in Workspaces.

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We're going to go back and
turn off errors with our .htaccess file.

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Now we can go back to our browser and
preview errors one.

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We see a blank white page.

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There aren't any parse errors because
we're not seeing the error page.

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So we can go in and
turn on errors just for this page.

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To tell the server we
want to display errors,

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we add two lines to the top of our PHP
file directly below the opening PHP tag.

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I've already added these lines,
but they're commented out.

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We'll remove the double
slashes before the two lines.

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The first is error reporting.

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This sets error reporting to all.

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The next one is the ini_set
display_errors.

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One means true, display errors on.

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I've also included the setting for
html_errors just in case.

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After saving the file,
let's refresh the browser.

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Awesome.

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We have a notice and a warning.

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Notice: Undefined variable: errors,

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in our errors1 on line 12.

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And our warning tells us that there's
an invalid argument supplied for

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foreach on line 12 as well.

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These are both telling us there's an error
on line 12, so let's take a look.

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Sure enough on line 12 we see that we
have tried to loop through an array named

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errors.

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But the actual array we
want is named error_levels.

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Let's change this name.

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And then we can save the page and
refresh the browser.

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Our errors are gone and
our page is working.

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Great job!

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You can also suppress errors for
a particular line using the @ symbol.

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This can be useful if you actually want to
allow things through without a warning or

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if you want to hide a warning for
short time.

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Let's go back into work spaces and
see this in action.

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Let's take a look at errors3.

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We have a file that has a bunch of errors.

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Let's see what happens when
we suppress those errors.

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The first one we see is a warning, and

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a fatal error that have to do with not
being able to open a required file.

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The call to this required
file is on line ten.

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If we suppress our call to required
field we can suppress our errors.

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There are no warnings, but the code
will stop because the file is required.

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So let's comment out that line for now.

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Now we see a few more warnings because
it failed to open files for include.

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These files are found on lines 13 and 16.

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Let's suppress line 13 and
also the file on line 16.

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Include files are not required.

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So if we suppress the warnings,
we can continue on.

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We see that we've stopped at line 16 and
displayed the message,

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failed to open file.

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That's because we told
our script to die or

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stop and display a message to the screen.

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You could argue that
this is a valid use for

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line suppression because we are actually
doing something with the error.

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Let's comment out this line and
see what else we have.

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Finally we have three more errors.

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The first is a warning telling us
that we're missing argument 1 for

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error function called on line 25 and
define on line 18.

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The second and third are both notices,

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and they tell us that we
have an undefined variable.

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The variable bad is at line 19 and
the variable error is on line 21.

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We can see on line 19 that bad is
actually an undefined variable.

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On line 21, the error variable is
the argument we're supposed to pass.

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Let's suppress our
function call on line 25.

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If we suppress our function call,
all three errors go away,

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even though our variable bad has nothing
to do with the missing argument.

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And it's probably something
that needs to be addressed.

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This should give you a sample of how and
when you might suppress errors and

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some of the issues that they can cause.

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Anytime you are suppressing
errors in any form,

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make sure this is actually what you want.

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Warnings are there for a reason.

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Line suppressions can make things
especially difficult to diagnose so

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use them sparingly and
only when necessary.

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Often exceptions are a much better way
to handle these types of situations.

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Don't forget to check the teacher's
notes for more information.