/*

* Given a string, return a new string where the first and last chars have been exchanged.

* frontBack("code") → "eodc"

* frontBack("a") → "a"

* frontBack("ab") → "ba"

*/

public class FrontBack {

//Class for testing and setting dummy values

public static void main( String [] args ) {

//Output tests

System.out.println( frontBack( "Hello World" ) );

}

public static String frontBack( String str ) {

if( str.length() < 1 ) {

return str;

}

else if( str.length() > 1 ) {

char first = str.charAt( 0 );

char last = str.charAt( str.length() - 1 );

return last + str.substring( 1, str.length()-1 ) + first;

} else {

return str;

}

}

}