$().each, $.each() , forEach

$().each()dom处理上用的比较多
$("input[type='checkbox']").each(function(i){
   $(this).attr("checked",true);
});

$.each()用于处理数组
var data=["a","b","c"];
$.each(data,function(index,value){
     alert(i+"..."+value);
});

forEach()用于遍历数组或对象
var data=["a","b","c"];
data.forEach(function(value,index){
    
})
var json={};
json.forEach(function(fesult){

})