int sum $=0$;

for $($int elem: arr$)$

r

sum $+=$ elem;

$$

$2.$

int$[][],$

$\{4,5,6\}$;

int$[]$ arrlD$=$ new int$[2]$;

int rownum $=0$;

for $($int$[]$ row : arr$2D$

$1$

rowNum