How to wait For loop's ending?

I am searching this question for a while and found some resources, but I cant understand these resources anyway.

for (item in itemList) {
    //Some foo
    console.log('Hello 1');
}

if (some equality) {      
   console.log('Hello 2'); 
}

And output is:

 Hello 2
 Hello 1

Somehow, If works before For loop. How can I fix that? Thanks.