Should a Function always Return Something?

**DoubleDee** · Sep 29, 2012 18:34

Below is a Function that I just created which returns a Section's Name...

PHP Code:


    function getSectionName($dbc, $slug){



        // Build query.

        $q1 = "SELECT name

                FROM section

                WHERE slug=?";



        // Prepare statement.

        $stmt1 = mysqli_prepare($dbc, $q1);



        // Bind variable to query.

        mysqli_stmt_bind_param($stmt1, 's', $slug);



        // Execute query.

        mysqli_stmt_execute($stmt1);



        // Store results.

        mysqli_stmt_store_result($stmt1);



        // Check # of Records Returned.

        if (mysqli_stmt_num_rows($stmt1)==1){

            // Section Found.



            // Bind result-set to variables.

            mysqli_stmt_bind_result($stmt1, $sectionName);



            // Fetch record.

            mysqli_stmt_fetch($stmt1);



            // Return Section Name.

            return $sectionName;



        }else{

            // Section Not Found.

            $resultsCode = 'FUNCTION_SECTION_NOT_FOUND_5010';



            // Set Error Source.

            $errorPage = $_SERVER['SCRIPT_NAME'];



            // Log Function Error.

            logError($dbc, $resultsCode, $errorPage);



            // End script.

            exit();



        }//End of CHECK FOR SECTION



    }

I am wondering if I should return a NULL or '' in the ELSE branch in addition to logging the Error?

If I don't do that, then in my calling script, I would have to check for a Null like this to avoid an error...

PHP Code:


    <title><?php echo (isset ($sectionName) ? $sectionName : '') ?> Section</title>

...which seems silly.

Suggestions?

Thanks,

Debbie

**logic_earth** · Sep 29, 2012 18:40

You are using "exit" at that moment execution stops nothing matters after that.

**DoubleDee** · Sep 29, 2012 19:15

Originally Posted by logic_earth

You are using "exit" at that moment execution stops nothing matters after that.

I am testing my code, and realizing that I have a bigger issue...

What I want to happen is this...

In "index.php" I have this line in my php section which comes before my HTML section...

PHP Code:


$sectionName = getSectionName($dbc, $slug);

And then a few lines later I have...

HTML Code:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
	"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">

<head>
	<!-- HTML Metadata -->
	<title><?php echo (isset ($sectionName) ? $sectionName : 'EMPTY') ?> Section</title>

If getSectionName() successfully finds the "Section Name" for the "Section Slug" in the URL, then I want it displayed in <title> and also below in my HTML code (not shown here).

If getSectionName() cannot find the "Section Name" for the "Section Slug" in the URL, then I want...

1.) To call this function so I can log the error...

PHP Code:


        // Log Function Error.

        logError($dbc, $resultsCode, $errorPage);

2.) I want to return something like the Zero-Length String, so my HTML page still loads and doesn't crash.

How can I have it both ways?!

Thanks,

Debbie

**Cups** · Sep 30, 2012 03:52

Define section name at the top of your function:

PHP Code:


    function getSectionName($dbc, $slug){

         $sectionName="";



        // if, (buts and maybes) {

        // do your stuff here

        // else chuck silent errors

        }



    // then no matter what happens:

    return $sectionName;

    }

You could develop that idea further if you wanted:

PHP Code:


    function getSectionName($dbc, $slug, $default = ''){

         $sectionName= $default;



    // do your stuff here

    // else chuck silent errors





    // then no matter what:



    return $sectionName;

    }

This would leave you open to using it like:

PHP Code:


echo sectionName($foo,$bar);

// OR adding something slightly more helpful

echo sectionName($foo,$bar, $siteName);

The cost is that you have an extra [optional] argument going into your function, some might find that ugly.

**DoubleDee** · Sep 30, 2012 08:11

logic_earth & Cups,

The way I fixed it was simply removing exit() in my logError() function, so that after that function is called, control just continues in the parent code and then I can keep my return "" in the ELSE branch of my code.

Thanks,

Debbie

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