We want an event to let our front$-$end know every time a new zombie was created, so the app can display it$.$

$1.$Declare an event called NewZombie. It should pass zombieId $($a uint$),$ name $($a string$),$ and dna $($a uint$).$

$2.$Modify the $\_$createZombie function to fire the NewZombie event after adding the new Zombie to our zombies array.

$3.$You're going to need the zombie's id$.$ array.push$()$ returns a uint of the new length of the array $-$ and since the first item in an array has index $0,$ array.push$()-1$ will be the index of the zombie we just added. Store the result of zombies.push$()-1$ in a uint called id$,$ so you can use this in the NewZombie event in the next line.

pragma solidity $>=0\mathrm{.}5\mathrm{.}0<0\mathrm{.}6\mathrm{.}0$;

contract ZombieFactory $\{$

$//$ declare our event here

uint dnaDigits $=16$;

uint dnaModulus $=10**$ dnaDigits;

struct Zombie $\{$

string name;

uint dna;

$\}$

Zombie$[]$ public zombies;

function $\_$createZombie$($string memory $\_$name, uint $\_$dna$)$ private $\{$

zombies.push$($Zombie$(\_$name, $\_$dna$))$;

$//$ and fire it here

$\}$

function $\_$generateRandomDna$($string memory $\_$str$)$ private view returns $($uint$)\{$

uint rand $=$ uint$($keccak$256($abi$.$encodePacked$(\_$str$)))$;

return rand $\%$ dnaModulus;

$\}$

function createRandomZombie$($string memory $\_$name$)$ public $\{$

uint randDna $=\_$generateRandomDna$(\_$name$)$;

$\_$createZombie$(\_$name, randDna$)$;

$\}$

$\}$