Don’t know why, but most of times I see the PHP unset() multilined with a only one parameter!?
unset($var1); unset($var2); unset($var3); |
But as you can see from the PHP doc page of unset() this method takes optional parameter count.
void unset(mixed $var [, mixed $var [, mixed $...]]) |
So perhaps a better solution can be:
unset($var1, $var2, $var3); |
It’s at least single lined!
Recently I wrote about list() in PHP which is indeed very powerful when assigning variable values from array elements.
$a = array(10, array('here', 'are', 'some', 'tests')); list($count, $list) = $a; |
Actually my example in the post was not correct, because I wrote that you can pass an associative array, but the truth is that you cannot, and thus the array should be always with numeric keys. After noticing the comments of that post, and thanks to @Philip, I searched a bit about how this problem can be overcome.
As always PHP gives a perfect solution! You can see on the list() doc page that there is a function that may help you use an associative array.
extract() is perhaps less known than list(), but it does the right thing!
$a = array('count' => 10, 'list' => array('here', 'are', 'some', 'tests')); extract($a); echo $count; // 10 print_r($list); // array('here'.... |
Note that now both $count and $list are defined.
First of all list() is not an unknown method in the PHP community, where almost every PHP developer knows what it does. The pity is that it has, perhaps, remained useless, although there is hidden power in it!
Let’s assume you’ve two variables and one array with two elements:
$arr = array(1, 2); $a = $arr[0]; $b = $arr[1]; // now a == 1, and b == 2 |
Maybe the easiest way to assign to the first variable the value of the first element of the array, and to the second variable the value of the second element of the array is to use list():
list($a, $b) = array(1, 2); // again a == 1, and b == 2 |
Note that you can do the same with as many variables/array elements you want.
The funny thing is that nobody use it, while I see at least one perfect usage. You can think of a typical admin panel of any web system. For sure any developer has programmed the typical table page containing a list of “things” and a paging to switch the result set page. It’s like the posts page from the WordPress admin panel, or a search result page in Google, where you’ve one page of results and at the bottom – a number of pages where you can go to another page of the search results.
What I’ve seen in almost every project is that typically the developers prefer to set the results for the page into one list returned from one method and the count of the entire result set is returned by another method.
Thus most of the times there are two methods, performing most commonly a database queries. Something like – getList($offset, $limit) and getCount() where the first one returns the page and the second one returns the count of the result set.
This will result into two methods, two calls and two lines of code:
function getList($offset, $limit) { ... // although the entire result set contains // 5 elements by limiting it from the parameters // only three are returned return $list; // where $list = array('title1', 'title2', 'title3'); } function getCount() { ... // here's returned the count // of the entire result set return $count; // where $count = 5; } $list = getList(0, 3); $count = getCount(); |
What actually you can do is to perform both queries in one method, perhaps called getItems($offset, $limit) where the returned value is an array containing both the list of results and the count:
function getItems($offset, $limit) { ... return array('list' => $list, 'count' => $count); } |
And finally when calling this method to list() that into the two variables – single lined.
list($list, $count) = getItems(0, 3); |
Today after two posts [#1, #2] in the past days here’s something that shows again the JavaScript power. This is not a complete example, but it’s good to start.
var str = '/text/1/text/2/'; var a = str.match(/(\d+)/gi); console.log(a); |
in that example you’ll get an array with all the numbers in the string [“1”, “2”] – yet another flexible js snippet!
After reviewing a chunk of my code for today I continue to admire the flexibility of JavaScript. It’s really powerful. In that example you can get a string split it by a given symbol to an array and than get the Nth element of it. All this on one line! Amazing!
var str = 'my-long-string'; str.split('-')[0]; // will contain "my" |
the 1st and 2nd indexes contain respectively “long” and “string”!