jQuery extend 命名空间 each 等讲解

extend(dest,src1,src2,src3...);
var newSrc=$.extend({},src1,src2,src3...)//也就是将"{}"作为dest参数

var result=$.extend({},{name:"Tom",age:21},{name:"Jerry",sex:"Boy"})

result={name:"Jerry",age:21,sex:"Boy"

$.extend({
hello:function(){alert('hello');}
});//合并到jQuery全局对象中

$.fn.extend({
hello:function(){alert('hello');}
});//合并到jQuery实例对象中

<script type="text/javascript">
$(document).ready(function (){
$.extend({jqueryAlert:function(){alert("jQuery类method!");}});
$.fn.extend({
alertWhileClick:function(){
alert("jQuery对象method!");
}
});
$.jqueryAlert();
});
</script>//比较

//基本扩展;
var newSrc1 = jQuery.extend(
{ name: "jonh", location: { city: "Boston" } },
{ last: "Resig", location: { state: "MA" } }
);
alert(newSrc1.location.city);

//深入扩展;
var newSrc2 = jQuery.extend( true,
{ name: "John", location: { city: "Boston" } },
{ last: "Resig", location: { state: "MA" } }
);
alert(newSrc2.location.city);

$.extend({net:[{name:"ggf"},{name:"jack"}]});
$.extend($.net,{
hello:function(){alert('hello');}
});
$(document).ready(function(){$.net.hello();alert($.net[1].name);});

$.extend({net:{}});
$.extend($.net,{
hello:function(){alert('hello');}
});
$(document).ready(function(){$.net.hello();alert($.net[1].name);});

$.each([1,2,3],function(i,val){
//var 就是循环到的实体;
//alert(i);次数
//alert(val);值
});
var obj = { one:"o", two:"t", three:"r", four:"f"};
$.each(obj, function(key, val) {
//alert(val.one);error
//alert(val.key);error
//alert(obj.key);error
//alert(obj.one);o o o o
//alert(key);  one two three four
//alert(val);o t r f
});
var obj2 = [{name:"Jack",age:22},{name:"Marry",age:21}];
$.each(obj2, function(key, val) {
//alert(key);1 2
//alert(val.name);Jack Marry
//alert(obj2[1].age);
});
}