jQuery method to determine whether an object exists_jquery

The example in this article describes how jQuery determines whether an object exists. Share it with everyone for your reference. The details are as follows:

1. Traditional Javascript writing method

obj = document.getElementById("someID"); 
if (obj){ 
   obj.innerText("hi"); 
} 

In jQuery, var obj = $("#id") returns object regardless of whether the id control exists, so if(obj) cannot be used to determine whether the control exists

2. jQuery determines whether the object exists

Method 1:

if ($('#target_obj_id').length > 0) {
//如果大于0 标识 id 为target_obj_id的对象存在，否则不存在 
   //对象存在的处理逻辑 
} else { 
   //对象不存在的处理逻辑 
}

Method 2:

if ($('#target_obj_id')[0]) { 
  //对象存在的处理逻辑 
} else { 
  //对象不存在的处理逻辑 
}

I hope this article will be helpful to everyone’s jQuery programming.