array.join('') doesn't work as expected

[thylakoids]

// original
Ye = ['p', 'r', 'o', 't', 'o', 't', 'y', 'p', 'e'].join('');
// deobfuscate
Ye = 'p,r,o,t,o,t,y,p,e';
// expect
Ye = 'prototype';