Empty string not showing in bash

Question

Hi, I am writing a script in bash, and I have a problem with an empty string, for example, I have this array

array=('Hello' '' 'World')                                                                    
echo ${array[@]}

and my conclusion

Hello (one space) World

but not

Hello (two spaces) World

Does anyone know why?

EDIT:

I was sorry that I need to use "" when I echo