Simon P :
I have an object in the form of
res = { 2019:
[
{id: 1, points: 435},
{id: 830, points: 230},
...
]
}
and an array seasons which is just a bunch of years => ["2015","2016",..."2019"]
seasons.forEach(season => {
res[season].forEach(item => {
console.log(item);
});
});
The snipped above logs each result correctly however I still get this error: Unhandled Rejection (TypeError): Cannot read property 'forEach' of undefined
Jon Warren :
You could use optional chaining to easily solve this. Simply add a question mark before the nested forEach
, like this:
seasons.forEach(season => {
res[season]?.forEach(item => {
console.log(item);
});
});
Note: As mentioned in the compatibility section of the linked doc, optional chaining is not yet supported by all browsers, so you might want to use a transpiler (like Babel)