How to compare arry

please help me

 char seach[]={'a','b','c','d'};
   char str_data[]={'a','b','d','c'};
    
     for (int z=0;z<4;z++) {
    
           Serial.println("str_data");
           Serial.println(str_data[z]);
           Serial.println("seach");
           Serial.println(seach[z]);
          
           if (str_data[i] != seach[i]){Serial.println("Arry not qual");}
           else { Serial.println("done equal \n");
        }
         

give result "Arry not qual" while first two element are same .
my expected result is
done equal
done equal
Arry not qual
Arry not qual

Please post code that compiles and provides the output that you posted

What is i?