how to assign an rest operator in javascript

function multiply(multiplier, ...theArgs) {
  return theArgs.map(element => {
    return multiplier * element
  })
}

let arr = multiply(2, 1, 2, 3)
console.log(arr)  // [2, 4, 6]
function addition(...nombre) {

    let resultat = 0
    
    nombre.forEach(nombre => {
       resultat+= nombre ;
    }); 

    console.log(resultat) ;
    
}

addition(4 ,9 ,5 ,415 ,78 , 54) ;