*C++* How can i get the number of items in my string array?

#include <iostream>
#include <string>
#include <stdlib.h>
#include <time.h>


int main()
{
    srand(time(NULL)); //random seed usign time

    

    std::string Helmets[] = {"None - Helmet" , "UNTAR - Helmet" , "Vulcan - Helmet" , "SSH-68 - Helmet" , "LZSh - Helmet" , "TC 800 - Helmet" , "Highcom Striker ACHHC IIIA - Helmet" , "ULACH IIIA - Helmet"  , 
                             "LZSh - Helmet"  , "Crye Precision Airframe - Helmet" };

    std::string BodyArmour[] = { "None - BodyArmour" , "6B43 Zabralo - BodyArmour" , "PACA - BodyArmour" , "6B13 - BodyArmour" , "Module 3M - BodyArmour" , "Zhuk-3 Press Armor - BodyArmour"
                                , "Korund VM - BodyArmour"  , "6B13 M Tan (Killa Armor) - BodyArmour"  , "BNTI Gzhel-K - BodyArmour" };

    std::string Gun[] = { "None - Primary" , "ADAR - Primary" , "M4A1 - Primary" , "AKM - Primary" , "ASH 12 - Primary" , "AS Val - Primary" , "MCX - Primary" , "OP SKS - Primary" , "Vepr Hunter - Primary"
                        , "P90 - Primary" , "PPSH - Primary" , "Vector 9x19 - Primary" , "M870 - Primary" , "TOZ-106 - Primary" , "M700 - Primary"  , "RSASS - Primary" };

    std::string Sidearm[] = { "None - Sidearm" , "Glock17 - Sidearm" , "M1911A1 - Sidearm" , "FN 57 - Sidearm" , "None - Sidearm" , "P226R - Sidearm" , "PM Pistol (Makarov) - Sidearm" , "TT - Sidearm" };

    std::string Rig[] = { "None - TacRig" , "Bankrobber - TacRig" , "Triton - TacRig" , "LBT-1961A - TacRig" , "WarTech Gear Rig - TacRig" , "Blackhawk Commando - TacRig" , "BlackRock - TacRig" , "Wartech MK3 - TacRig"
                        , "Velocity Systems Multi-Purpose Patrol Vest - TacRig" };

    std::string Backpack[] = { "None - Backpack" , "Blackjack 50 - Backpack" , "Attack 2 - Backpack" , "Scav BP - Backpack" , "Duffle Bag - Backpack" , "Sanitar Bag - Backpack" , "VKBO Army Bag - Backpack"
                              , "LK 3F Transfer Tourists Bag - Backpack" , "Ana Tactical Beta 2 - Backpack" , "Camelbak Tri-Zip - Backpack" , "Oakley Mechanism - Backpack" , "3V G Paratus - Backpack" };

    **int randomHelmNum = rand() % sizeof(Helmets);
    int randomBArmourNum = rand() % sizeof(BodyArmour);
    int randomGunNum = rand() % sizeof(Gun);
    int randomSidearmrNum = rand() % sizeof(Sidearm);
    int randomRigNum = rand() % sizeof(Rig);
    int randomBackPackNum = rand() % sizeof(Backpack);**
    

    std::cout << std::endl << std::endl << Helmets[randomHelmNum] << std::endl << BodyArmour[randomBArmourNum] << std::endl << Gun[randomGunNum]
    << std::endl << Sidearm[randomSidearmrNum] << std::endl << Backpack[randomBackPackNum] << std::endl << Rig[randomRigNum] << std::endl << std::endl;

    
}

**

Hello, Im trying to create a random gear set using arrays but I want the Rand % to dynamically update with items in the array is their a way to do this?

Hello, Im trying to create a random gear set using arrays but I want the Rand % to dynamically update with items in the array is their a way to do this? **