jquery Determines whether an object is empty and traverses a simple instance of the object
- 2021-07-06 09:45:03
- OfStack
javascript:
if(document.getElementById("target_obj_id")){
} else {
}
jquery:
This does not work because $("# target_obj_id") returns object regardless of whether the object exists or not
1.
var target_obj = jQuery('#target_obj_id');
if (target_obj.length > 0) { // If greater than 0 Identification id For target_obj_id The object of exists, otherwise it does not exist
} else {
}
2 ,
if (target_obj[0]) {
} else {
}
3. $.isEmptyObject({}) // true
$.isEmptyObject({ foo: "bar" }) // false
// Judge and traverse each object
if($("#t_specialsearch select").length <= 0){
alert(" Object is empty ");
}else{
//console.log($("#t_specialsearch select")[0]);
$("#t_specialsearch select").each(function(){
//alert($(this));
console.log($(this));
});
for(var i in $("#t_specialsearch select")){
console.log($("#t_specialsearch select")[i]);
}
}
1 step 1 footprint, convenient for their own review, the shot when the shot, there are mistakes, 1 must correct, thank you very much, common progress!