How to know the value is empty

Question

If I pass an empty array to jade, how can I know if is empty?

Javascript:

var data = [];

Jade:

if(data) 
   table ...
else 
   table ...

Answer 1

Use length property:

if (data.length)
    table ...
else
    table ...

Answer 2

you can use javascript to check the length of the array.

if (data.length==0){
  // do something array is empty
}

here is a related answer https://stackoverflow.com/a/5071150/3556874