如何在JavaScript中查找特定的数组变量是否为空？

Question

I have an array variable like Array[0] , and now I need to check whether that Array[0] contains value or not inside of it. What should I do?

Answer 1

If you have an array and call it eg. list , then you can check if it has some elements in the following manner:

if (list.length){
    // has some elements (exactly list.length elements)
} else {
    // does not have any elements
}

See the following for details: Documentation on length property of Array objects in JavaScript

Answer 2

Checks if that array exists and does something if not so.

if(!array[0])
{
  //do something
}

Answer 3

if(array[0] !== undefined){
 // array[0] is defined.
}

Answer 4

//pass array variable to this function

function isEmpty(array){
   if(array.length == 0)
    return true;
   else
    return false; 
}