PHP array_push()

array_push() appends one or more elements to an array. The function returns the number of total elements of the array.
   int array_push(array [, mixed values])

<?PHP
	$arr=array(1,2,3,4);
    $ret=array_push($arr,5);
	echo "$ret"; //5
	foreach($arr as $element) echo "$element, "; //1, 2, 3, 4, 5, 
    $ret=array_push($arr,5,6,7);
	echo "$ret"; //8
	foreach($arr as $element) echo "$element, "; //1, 2, 3, 4, 5, 5, 6, 7, 
?>

If you want to append elements to an associative array, just define the key and values.

<?PHP
	$arr=array("apple"=>"carbon","rice"=>"carbon","nuts"=>"fat");
	$arr["meat"]="protein";
    foreach($arr as $key=>$val) echo "$key, $val; ";
	//apple, carbon; rice, carbon; nuts, fat; meat, protein;
?>

You may use array_merge() to simulate the array_push function.

<?PHP
	$arr=array("apple"=>"carbon","rice"=>"carbon","nuts"=>"fat");
	$arr=array_merge($arr,array("meat"=>"protein"));
    foreach($arr as $key=>$val) echo "$key, $val; ";
	//apple, carbon; rice, carbon; nuts, fat; meat, protein; 
?>

array_pop() retrieves the last element of an array, at the same time delete the element from the array. If the array is empty, or the parameter is not an array, return NULL. array_unshift() adds elements to the beginning position of an array.

<?PHP
	$arr=array("apple","orange","peach","blueberry");
    $ret=array_pop($arr);
	echo "$ret";  //blueberry
	foreach($arr as $element) echo "$element, ";  //apple, orange, peach, 

	$ret = array_unshift($arr, 88);
	echo "$ret"; //4
    print_r($arr);	
	//the result is:
	Array
	(
		[0] => 88
		[1] => apple
		[2] => orange
		[3] => peach
	)
?>