Shell Script | AWK | Variable inside FOR-Loop

Hi!

I am new to OSX Shell Script and am trying to work my way into it. I don't get the expected outcome with the following snippet of my script code and I have no idea, why. I read most of the Apple Shell Script Pimer and googled a lot about it, but to no avail.

I want to check the current username against some given usernames and set the value of a variable depending on the outcome. I used awk inside the shell script to get this done, but for some reason the for loop inside the awk part seems to change the value of the current username with every loop.

This is the code:

#!/bin/zsh

awk -v u=$USER 'BEGIN {
       print "Username outside loop is " u;

      count[0] = "Anton";
      count[1] = "Bert";
      count[2] = "Carl";                          

      for ( c_num in count ) {
             print "Username inside loop is " u;
             print "Compare to "count[c_num];                                    
             if (u = count[c_num]) {
                  test_var = "X";
             } else {
                  test_var = "Y";
             }
            print test_var;
      }
}'

And this is what I get after I run it in terminal:

Username outside loop is Zac
Username inside loop is Zac
Compare to Carl
X
Username inside loop is Carl
Compare to Anton
X
Username inside loop is Anton
Compare to Bert
X

I don't see why 'u' is changed every loop.

I'm thankful for every help / advice!

Markus