Nej jQuery är inte inbyggt i HTML5.
//Ett objekt returneras, selector i detta kontext är '#minknapp'
jQuery = function( selector, context ) {
// The jQuery object is actually just the init constructor 'enhanced'
return new jQuery.fn.init( selector, context, rootjQuery );
}
//Objektet i sin tur har följande logik på sig
jQuery.fn = jQuery.prototype = {
constructor: jQuery,
init: function( selector, context, rootjQuery ) {
var match, elem, ret, doc;
// Handle $(""), $(null), $(undefined), $(false)
if ( !selector ) {
return this;
}
// Handle $(DOMElement)
if ( selector.nodeType ) {
this.context = this[0] = selector;
this.length = 1;
return this;
}
// Handle HTML strings
if ( typeof selector === "string" ) {
if ( selector.charAt(0) === "<" && selector.charAt( selector.length - 1 ) === ">" && selector.length >= 3 ) {
// Assume that strings that start and end with <> are HTML and skip the regex check
match = [ null, selector, null ];
} else {
match = rquickExpr.exec( selector );
}
// Match html or make sure no context is specified for #id
if ( match && (match[1] || !context) ) {
// HANDLE: $(html) -> $(array)
if ( match[1] ) {
context = context instanceof jQuery ? context[0] : context;
doc = ( context && context.nodeType ? context.ownerDocument || context : document );
// scripts is true for back-compat
selector = jQuery.parseHTML( match[1], doc, true );
if ( rsingleTag.test( match[1] ) && jQuery.isPlainObject( context ) ) {
this.attr.call( selector, context, true );
}
return jQuery.merge( this, selector );
// HANDLE: $(#id)
} else {
elem = document.getElementById( match[2] );
// Check parentNode to catch when Blackberry 4.6 returns
// nodes that are no longer in the document #6963
if ( elem && elem.parentNode ) {
// Handle the case where IE and Opera return items
// by name instead of ID
if ( elem.id !== match[2] ) {
return rootjQuery.find( selector );
}
// Otherwise, we inject the element directly into the jQuery object
this.length = 1;
this[0] = elem;
}
this.context = document;
this.selector = selector;
return this;
}
// HANDLE: $(expr, $(...))
} else if ( !context || context.jquery ) {
return ( context || rootjQuery ).find( selector );
// HANDLE: $(expr, context)
// (which is just equivalent to: $(context).find(expr)
} else {
return this.constructor( context ).find( selector );
}
// HANDLE: $(function)
// Shortcut for document ready
} else if ( jQuery.isFunction( selector ) ) {
return rootjQuery.ready( selector );
}
if ( selector.selector !== undefined ) {
this.selector = selector.selector;
this.context = selector.context;
}
return jQuery.makeArray( selector, this );
},
// Start with an empty selector
selector: "",
// The current version of jQuery being used
jquery: "1.8.3",
// The default length of a jQuery object is 0
length: 0,
// The number of elements contained in the matched element set
size: function() {
return this.length;
},
toArray: function() {
return core_slice.call( this );
},
// Get the Nth element in the matched element set OR
// Get the whole matched element set as a clean array
get: function( num ) {
return num == null ?
// Return a 'clean' array
this.toArray() :
// Return just the object
( num < 0 ? this[ this.length + num ] : this[ num ] );
},
// Take an array of elements and push it onto the stack
// (returning the new matched element set)
pushStack: function( elems, name, selector ) {
// Build a new jQuery matched element set
var ret = jQuery.merge( this.constructor(), elems );
// Add the old object onto the stack (as a reference)
ret.prevObject = this;
ret.context = this.context;
if ( name === "find" ) {
ret.selector = this.selector + ( this.selector ? " " : "" ) + selector;
} else if ( name ) {
ret.selector = this.selector + "." + name + "(" + selector + ")";
}
// Return the newly-formed element set
return ret;
},
// Execute a callback for every element in the matched set.
// (You can seed the arguments with an array of args, but this is
// only used internally.)
each: function( callback, args ) {
return jQuery.each( this, callback, args );
},
ready: function( fn ) {
// Add the callback
jQuery.ready.promise().done( fn );
return this;
},
eq: function( i ) {
i = +i;
return i === -1 ?
this.slice( i ) :
this.slice( i, i + 1 );
},
first: function() {
return this.eq( 0 );
},
last: function() {
return this.eq( -1 );
},
slice: function() {
return this.pushStack( core_slice.apply( this, arguments ),
"slice", core_slice.call(arguments).join(",") );
},
map: function( callback ) {
return this.pushStack( jQuery.map(this, function( elem, i ) {
return callback.call( elem, i, elem );
}));
},
end: function() {
return this.prevObject || this.constructor(null);
},
// For internal use only.
// Behaves like an Array's method, not like a jQuery method.
push: core_push,
sort: [].sort,
splice: [].splice
};
jQuery ÄR javascript, det jQuery gör är att wrappa vanlig javascript för att göra det enklare för gemene man att programmera i det.
Är jQuery lika snabbt som vanlig javascript? Nej.
Kan man göra mer i jQuery med mindre kod? Ja. Men inte bakom scenerna (se exempel ovan).
Innan du börjar använda diverse javascript-bibliotek (finns hur många som helst) skulle jag tipsa om att lära sig grunderna i javascript först. Detta ger en enorm kunskapsbas att stå på när du sedan går på ett javascript-ramverk eller bibliotek.