JQuery: Difference between revisions
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JQuery is a JavaScript popular framework. It smooths over many of the difficulties that traditionally made JavaScript hard to work with and supports / encourages a unique style of coding driven by CSS-selector based "queries". JQuery code can be surprisingly compact. By default jQuery is accessed via the globally defined function "$" (though "jQuery" should also work). | |||
For example, to hide all the links (in anchor tags) on a page, you could simply write: | |||
<source lang="javascript"> | |||
$("a").hide(); | |||
</source> | |||
Or to make all paragraphs of class "quote" have a pink background, and a larger text size: | |||
<source lang="javascript"> | |||
$("p.quote").css({background: "pink", font-size: "larger"}); | |||
</source> | |||
http://jquery.org | |||
* [http://www.linuxjournal.com/article/10404 Writing jQuery Plugins, tutorial] | |||
== JQuery == | |||
http://jquery.org | http://jquery.org | ||
* Smooths over browser differences (Event-handling, AJAX) | |||
* Incredibly elegant: CSS selectors to "query" the page & manipulate specific content with code | |||
* Pre-fab widgets & behaviors (Draggable, Resizable, Droppable) | |||
== JQuery: Hello world == | |||
<source lang="html4strict"> | |||
<html> | |||
<head> | |||
<script src="jquery.js"></script> | |||
<script> | |||
$(document).ready(function () { | |||
console.log("Hello world"); | |||
}); | |||
</head> | |||
<body> | |||
</body> | |||
</html> | |||
</source> | |||
== JQuery: Styles Plus == | |||
<source lang="html4strict"> | |||
<html> | |||
<head> | |||
<script src="jquery.js"></script> | |||
<script> | |||
$(document).ready(function () { | |||
$("p.foo").css({'background': 'pink'}); | |||
}); | |||
</head> | |||
<body> | |||
<p class="foo">Hello</p> | |||
<p>World</p> | |||
</body> | |||
</html> | |||
</source> | |||
== Extreme Functions == | |||
Javascript functions can be defined "in-place" and be "anonymous". | |||
Traditional for loop: | |||
<source lang="javascript"> | |||
var words = "Once upon a time, in a galaxy far far away".split(" ") | |||
for (var i=0; i<words.length; i++) { | |||
console.log(words[i]); | |||
} | |||
</source> | |||
Using jQuery's each: | |||
<source lang="javascript"> | |||
var words = "Once upon a time, in a galaxy far far away".split(" ") | |||
$(words).each(function (i, w) { | |||
console.log(w); | |||
}); | |||
</source> | |||
There are situations where using each is important! (For making proper closures) | |||
== JQuery: Events == | |||
<source lang="html4strict"> | |||
<html> | |||
<head> | |||
<script src="jquery.js"></script> | |||
<script> | |||
$(document).ready(function () { | |||
$("p").click(function () { | |||
$(this).css({background: "aqua"}); | |||
}); | |||
}); | |||
</head> | |||
<body> | |||
<p class="foo">Hello</p> | |||
<p>World</p> | |||
</body> | |||
</html> | |||
</source> | |||
Latest revision as of 10:55, 16 February 2021
JQuery is a JavaScript popular framework. It smooths over many of the difficulties that traditionally made JavaScript hard to work with and supports / encourages a unique style of coding driven by CSS-selector based "queries". JQuery code can be surprisingly compact. By default jQuery is accessed via the globally defined function "$" (though "jQuery" should also work).
For example, to hide all the links (in anchor tags) on a page, you could simply write:
$("a").hide();
Or to make all paragraphs of class "quote" have a pink background, and a larger text size:
$("p.quote").css({background: "pink", font-size: "larger"});
JQuery
- Smooths over browser differences (Event-handling, AJAX)
- Incredibly elegant: CSS selectors to "query" the page & manipulate specific content with code
- Pre-fab widgets & behaviors (Draggable, Resizable, Droppable)
JQuery: Hello world
<html>
<head>
<script src="jquery.js"></script>
<script>
$(document).ready(function () {
console.log("Hello world");
});
</head>
<body>
</body>
</html>
JQuery: Styles Plus
<html>
<head>
<script src="jquery.js"></script>
<script>
$(document).ready(function () {
$("p.foo").css({'background': 'pink'});
});
</head>
<body>
<p class="foo">Hello</p>
<p>World</p>
</body>
</html>
Extreme Functions
Javascript functions can be defined "in-place" and be "anonymous".
Traditional for loop:
var words = "Once upon a time, in a galaxy far far away".split(" ")
for (var i=0; i<words.length; i++) {
console.log(words[i]);
}
Using jQuery's each:
var words = "Once upon a time, in a galaxy far far away".split(" ")
$(words).each(function (i, w) {
console.log(w);
});
There are situations where using each is important! (For making proper closures)
JQuery: Events
<html>
<head>
<script src="jquery.js"></script>
<script>
$(document).ready(function () {
$("p").click(function () {
$(this).css({background: "aqua"});
});
});
</head>
<body>
<p class="foo">Hello</p>
<p>World</p>
</body>
</html>