Tag Archives: Curly bracket programming languages

Object Oriented JavaScript: Inheritance

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Objects and JavaScript

JavaScript, being a functional language, differs from most of the procedural/object oriented languages we know. The object oriented approach in JavaScript is rather strange. However there is much power in making objects! The syntax is really odd and there are several approaches.

Literal Notation

As many of you may know the most used notation is the JSON (JavaScript Object Notation).

{ 'key1' : 'val1'
, 'key2' : 'val2'
, 'key3' : 'val3'
}

Of course this is the very basic example. You can use as value any JavaScript object – another similar object or a function.

{ 'key1' : 'val1'
, 'key2' : { 'inner_key1' : 'inner_val1' }
, 'key3' : function() {
			return 10 + 5;
		 }
}

The two examples above are showing an anonymous object in JavaScript, but you can assign this code to some variable.

var myObject = 
	{ 'key1' : 'val1'
	, 'key2' : 'val2'
	, 'key3' : 'val3'
	}

or

var myObject =
	{ 'key1' : 'val1'
	, 'key2' : { 'inner_key1' : 'inner_val1' }
	, 'key3' : function() {
				return 10 + 5;
			 }
	}

and then you can call the properties of these objects with the ‘.’ operator:

myObject.key1;
myObject.key2.inner_key1;
myObject.key3();

So far so good – this is the literal object notation in JavaScript. However there is another “objects” in JavaScript.
Continue reading Object Oriented JavaScript: Inheritance →

JavaScript Objects Coding Style Reviewed

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JS Objects

Once I posted about JavaScript object coding style. Back than I made the analogy with PHP array coding style. In breve it’s useful to format the arrays in PHP simply like that:

$data = array(
	'key1' => 'value1',
	'key2' => 'value2',
	'key3' => 'value3',
	'key4' => 'value4',
	'key5' => 'value5',
);

Note that there is a trailing comma after the last key/value pair. This is not a syntax error and helps you add new elements to the array with no fear to forget the comma. This coding standard is quite well known in the PHP community, but in fact writing JavaScript objects can be “translated” to something very similar. The only problem is that the trailing comma in JavaScript will result to an error, especially in Internet Explorer, so it is important to remove it.

var obj = {
	key1 : 'value1',
	key2 : 'value2',
	key3 : 'value3',
	key4 : 'value4',
	key5 : 'value5'
};

The problem is that when you’ve to add one key/value pair, you’ve to add the comma after the last pair. This actually makes it useless.

Better Solution

There is another way, much better I think, that may help you more when adding new pairs to the object.

var obj = 
	{ key1 : 'value1'
	, key2 : 'value2'
	, key3 : 'value3'
	, key4 : 'value4'
	, key5 : 'value5'
	};

In this example you can simply copy/paste the last pair and change the key and value, or you can simply can continue writing the way the object is constructed.

Thus you don’t have the problem with the last comma and syntax errors.

HTTP POST with PHP without cURL

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Awesome PHP

a great php idea!
It’s strange how powerful PHP can be. There’s a legend that cURL is the only way to perform a HTTP POST with PHP, but that isn’t the truth. An extremely useful script is by using stream_context_create:

$optional_headers = null;
$params = array('http' => array(
                'method' => 'POST',
                'content' => http_build_query(array('name' => 'my-name'))));
 
if ($optional_headers !== null) {
    $params['http']['header'] = $optional_headers;
}
 
$ctx = stream_context_create($params);
$fp = @fopen('http://example.com/post.php', 'rb', false, $ctx);

Well this is only a snippet. You can change a lot this code and perform any request, but here’s a small start up. However note that this will do the same as while posting to example.com/post.php via web form!

Flexible JavaScript – Replace in a String

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Here’s yet another example of the JavaScript flexibility. You can simply call .replace() on every string and pass a regex as a parameter!

var str = 'my simple string';
str.replace(/ /g, '-'); // now 'str' will contain 'my-simple-string'

Flexible JavaScript – Splitting Strings

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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”!