recursion - understanding compareto() method in java -

i came across mit lecture on recursion checked palindrome using recursion,and there checked using logic compare first , last alphabet , on.. thought follows

just pseudo code:

    string original="abba";      string reverse = "";     for(int i=original.length()-1;i>=0;i--)     {         reverse+=new string(original.substring(i,i+1));     }     if(original.equals(reverse))         system.out.println("palindrome");     else         system.out.println("not palindrome"); 

i have 2 doubts

• is logic better recursion or conventional logic in terms of time complexity?
• how compareto() method checks if strings equal? compare bytecode or something?

you should use equals, not compareto, since compareto returns int , not boolean if condition expect. alternately can check if (original.compareto(reverse)==0), means strings equal.

as how compareto works, compares each pair of characters having same index, , returns difference between first non equal pair. if equal, 0 returned.