ES6/JS assign default value if array.find returns undefined

I see this has been answered but I thought this could contribute

const { amount = 0 } = response.data.find(t => t.paymentType === 'RF' && t.status === 1) || {};
this.statistics.creditAmount = amount;

Or you could use a reducer:

  this.statistics.creditAmount = response.data.reduce((amt, t) => t.paymentType === 'RF' && t.status === 1 ? t.amount : amt, 0);

The reducer would use more clock cycles as it traverses the entire array, whereas Array.prototype.find stops once it reaches the first match. This may cause the results to vary as well, since the way that reducer is written it will take the last item from the array that matches.

The problem with your code is that you're accessing .amount of undefined for cases where array.find returns undefined. You can solve it by adding a guard:

const credit = response.data.find(t => 
  t.paymentType == 'RF' && t.status == 1);

this.statistics.creditAmount = credit ? credit.amount : 0;

Another approach is to use a closure and a destructuring with a default object/value.

const
    getAmount = ({ amount = 0 } = {}) => amount,
    credit = getAmount(response.data.find(t => t.paymentType == 'RF' && t.status == 1));

Possible overkill, but you could create and implement a reusable null propagation method.

const response = {data: []};

const _try = (func, fallbackValue) => {
    try {
        var value = func();
        return (value === null || value === undefined) ? fallbackValue : value;
    } catch (e) {
        return fallbackValue;
    }
}


const result = _try(() => response.data.find(t => t.paymentType == 'RF' && t.status == 1).amount, 0);
console.log(result);

This was originally written by tocqueville as part of this answer.