what output is produced by the following program? please explain why

public class RelationalExpression$4\{$

public static void printRange$($char starLetter, char endLetter$)\{$

for $($char letter $=$ starLetter; letter $<=$ endLetter; letter$++)\{$

System.out.print$($letter$)$;

$\}$

System.out.println$()$;

$\}$

public static void main$($String$[]$ args$)\{$

printRange$(\text{'}$e$\text{'},\text{'}$g$\text{'})$;

printRange$(\text{'}$n$\text{'},\text{'}$s$\text{'})$;

printRange$(\text{'}$z$\text{'},\text{'}$a$\text{'})$;

printRange$(\text{'}$q$\text{'},\text{'}$r$\text{'})$;

$\}$

$\}$