Как подсчитать сумму в массиве?

let arr=[ 
    {id: 44,  bet: 2, cmon: 3,  lroom: 1000}, 
    {id: 45,  bet: 1, cmon: 20, lroom: 1000}, 
    {id: 432, bet: 2, cmon: 4,  lroom: 1000}, 
    {id: 45,  bet: 1, cmon: 30, lroom: 1000} 
  ]; 
     
var res = arr.reduce((acc, v) => { 
              let key =  v.bet == 1 ? 'red' : 'black'; 
              acc[key] += v.cmon; 
              return acc; 
           }, { red: 0, black: 0 } )    ; 
            
console.log(res);

let arr=[ 
    {id: 44,  bet: 2, cmon: 3,  lroom: 1000}, 
    {id: 45,  bet: 1, cmon: 20, lroom: 1000}, 
    {id: 432, bet: 2, cmon: 4,  lroom: 1000}, 
    {id: 45,  bet: 1, cmon: 30, lroom: 1000} 
  ]; 
     
     
var {1:red, 2:black} = arr.reduce((acc, v) => (acc[v.bet] += v.cmon, acc), { 1: 0, 2:0 } ); 
            
console.log(red, black);