PHP Functions 101 – array_push()

Hello and welcome back for my next installment of PHP Functions 101. This week I’ll be discussing the array_push() function. This is another simple function that I use often when dealing with arrays. Here is the definition from php.net:

Push one or more elements onto the end of array

This is a simple function. As the definition states above it simply pushes an element onto an existing array. You can push any kind of element; an object, simple variables, even other arrays. The function takes at least two parameters. The first being the array we are adding (pushing) the elements onto and the remaining variables are the elements to be added (pushed) onto the array. You can push as many elements on as you want.

Here are a couple examples. I’ll do a simple one then a more complex example.

// The big 'ol array that stores everything
$bigOlArray = array();

// Simple variables
$someString = "This is a simple string";
$someInteger = 42;
$configurationArray = array(
    "id" => "x302",
    "power" => "Asgard",
    "weapons" => true,
    "shields" => true,
    "shieldLevels" => 100
    );
$strikeFirst = false;

// Push them all into the same array
array_push($bigOlArray, $someString, $someInteger, $configurationArray, $strikeFirst);

With this example we simple made the main array, $bigOlArray, and then created a bunch of different variables then pushed them all onto the one array. This next example will hopefully be a more practical use of the funciton. I will use it to read in a file and take all the configuration info from the file and combine it into an array using the array_push() function.

/* Open the file we want to read in */
$fh = fopen("/path/to/file/the_file",'r');

if (!$fh) {
    // Put error checking code here
    exit();
} else {
    $elementData = array();
    $temp = array();
    $newField = false;
    $value = "";

    // Loop through the file
    while (!feof($fh) {
        $line = fgets($fh);
        if (strstr($line,'[END FIELD]')) {
            if ($newField) {
                /* Put the temp config array into the element array */
                array_push($elementData,$temp);
            }
            $newField = false;
            $temp = array();
        } else  if (strstr($line,'[FIELD]')) {
            $newField = true;
        }

        if ($newField) {
            /* Add the configuration line to the temp array */
            $ft = explode(" = ",$line);
            if (isset($ft[1])) {
                if (trim($ft[1]) == "true") {
                    $value = true;
                } else if (trim($ft[1]) == 'false') {
                    $value = false;
                } else {
                    $value = trim($ft[1]);
                }
                $temp[$ft[0]] = $value;
            }
        }
    }
}

/* Close the file */
fclose($fh);

What this script does is read in a file, then it searches for field definitions. Once it finds one it reads each line of the field definition into a temp array. Once it reaches the end it pushes the entire array onto the end of the main elements array. The script keeps this up till it reaches the end of the file where it then closes the connection to the file. PHP does have a function called parse_ini_file() which will do basically the same thing. It reads a configuration file and returns it as an associative array. I’m hoping though that the example above gave some insight in how you can use the function and the power it can have.

Well I hope this has brought something to a few readers out their. I haven’t decided yet what I will do for next week. Maybe It’ll probrably be one of the various string funcitons like strstr() or str_replace() or something similar. As always if you have any requests let me know 🙂

Thanks for reading!
– Miah

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