Accessing a variable in different methods Java -

i studying methods , have been given exercise do. bit unsure particular question.

the question have been given is:

    modify above program conversion done in method. 

this code have far , problem when run code far when enter letter , stops.

   //exercise 3 brian sheet 5 

//modify above program conversion done in method

import java.util.scanner;  public class exercise3 {  public static void main(string[] args) {     double temp;     string c = "c";     string f = "f";     string a;     scanner input = new scanner(system.in);      system.out.println("please enter temperature: ");     temp = input.nextdouble();      input = new scanner(system.in);      system.out             .println("please enter whether wish convert celsius or fahrenheit(c or f)");     = input.nextline();     if (a.equals(c)) {         celsiuseq(temp);     } else {         fahren(temp);     }  }  private static double celsiuseq(double celsius) {     double temp;     celsius = (temp - 32) * 5 / 9;     return celsius;  }  private static double fahren(double fahrenheit) {     double temp;     fahrenheit = temp * 9 / 5 + 32;     return fahrenheit; } 

} don't know doing wrong , simple. if me, graciously appreciated have been looking @ past 30 minutes!

here need interchange temp , celsius varables work

private static double celsiuseq(double celsius) {         double temp; //here problem         celsius = (temp - 32) * 5 / 9;         return celsius;      } 

here need interchange temp , fahrenheit varables work

 private static double fahren(double fahrenheit) {         double temp; //here problem         fahrenheit = temp * 9 / 5 + 32;         return fahrenheit;     } 

correction here

private static double celsiuseq(double temp){     double celsius;     celsius = (temp - 32) * 5 / 9;     return celsius;  }  private static double fahren(double temp){     double fahrenheit;     fahrenheit = temp * 9 / 5 + 32;     return fahrenheit; } 

update request

returntype functionname(argumenttype argument2 ,argumenttype argument2,....argumenttype argumentn  ){ // local variable declaration variableype variable1; variableype variable2; ---------------------- variableype variablen;  calculation     return value based on return type;   } 

see more details here

http://www.tutorialspoint.com/java/java_variable_types.htm

http://docs.oracle.com/javase/tutorial/java/javaoo/variables.html

http://docs.oracle.com/javase/tutorial/java/javaoo/arguments.html