A quick way to check for the running version of jQuery in your code:
if (jQuery.fn.jquery < '1.3.2')
console.log('yes');
jQuery each function
jQuery has done it again with a very succinct function to iterate over the values of a set and perform an action for each one. The each function is easy to use and keeps your code from being cluttered with many for loops.
var allAlts = new Array();
$('img').each(function(){
allAlts.push(this.alt);
});
These few lines of code will get the alt attribute of every image tag in your document and store it in an array.
Passing HashMap as POST parameter
If you would like to pass a hashmap as a parameter to a POST call in JavaScript, you need to use the dot notation and it will be interpreted as belonging to a hashmap. The code below loops through the properties of an object called ‘options’ and adds each one except for the toString() method to the POST parameter hashmap.
===================================================
Declaration of options variable
var options = {
foo: 'blah',
boo: 'muah',
toString: function() {
return this.foo + ', ' + this.boo;
}
};
===================================================
Inside AJAX call function
if (options != null) {
for (property in options) {
if (property != 'toString')
post_data['options.' + property] = options[property];
}
}
Using this code when you access the POST parameters on the server side, you can reference the ‘options’ POST parameter as a hashmap, i.e. options[‘foo’].
Javascript Object declared within another Object
In order to declare a Javascript object inside another one you would need to enter code similar to what is below.
var book = {
title: 'Nothing new!',
author: {name: 'Annyce', email:'[email protected]'}
};
You could then reference the author’s name via:
book.author.name
and if you wanted to update the name of the author, you would use
book.author.name = ‘Sarah’;
This feature of Javascript becomes very useful when you attempt to create an object with default settings and so forth.