java - Why is my code telling me to initialize a variable that is already initialized? -

i have below code:

public string palindrome(string str) {     string str, reverse = "";     scanner in = new scanner(system.in);     int length = str.length();     ( int = length - 1; >= 0; i-- )         reverse = reverse + str.charat(i);     if (str.equals(reverse))         system.out.println("entered string palindrome.");     else         system.out.println("entered string not palindrome.");      return ""; } 

it has init() method calls when character 'p' typed , check whether current string palindromic or not.

however ,when compile states there error in line:

string str, reverse = ""; 

the error states variable may not have been initialized. however, when initialize error message comes stating str has been initialized.

you have str duplicated, once parameter , once local variable. besides that...

string str, reverse = "";

...does initialize reverse "", not str:

string str, reverse = ""; system.out.println(str); // error here "the local variable str may not have been initialized" 

but...

string str = "", reverse = ""; system.out.println(str); // works fine