Trying to check if int[] is empty Java

Question

Simple, I am trying to check if int[] distances is empty or not.

Why does this not work?

My Code:

int[] distances = {3,6,7,6,1,8,8,2,3,4,5,9};

    if(distances != null && !distances.isEmpty()) {
        throw new TransportException("No routes in entry");
    }
        else {

    return distances;
    }

Answer 1

There is no isEmpty() method you can call on simple arrays. Just compare its length to 0.

if (distances == null || distances.length == 0)

Answer 2

Java arrays don't have any method except the ones declared on java.lang.Object.

The only attribute they have is length, which is the length of the array. So you need

if (distances != null && distances.length > 0)

Read the Java tutorial about arrays. Or read an introductory Java book.

Answer 3

if(distances != null && !distances.isEmpty()) 

condition ensures that :"Throw an exception when my array is not null and it contains some values.So it throws an exception whenever your array is NOT empty. I do not think that this is what you want.