code:
window.reddit.comments("uq0mzi").sort('hot').fetch(function(res) {
res[1].data.children.flatMap((item) => {
console.log(item.data.body)
item.data.replies.data.children.map(y => (y.data.body === undefined ? "" : console.log(" >>>"+y.data.body)))
})})
what I'm trying: I'm using the reddit API wrapper to get comments and their replies of a post. first map prints out the top level comments, while the second map is supposed to print out the replies to those comments
where its going wrong: the code works, but after printing everything, I'm getting a type error saying:
Uncaught TypeError: Cannot read properties of undefined (reading 'children')
how do I fix it?
My favorite solution is to use getSafe function to avoid undefined errors.
If a nested value is undefined, a default value will be returned instead of undefined
const getSafe = (fn, defaultVal) => {
try {
if (fn() === undefined || fn() === null) {
return defaultVal
} else {
return fn();
}
} catch (e) {
return defaultVal;
}
}
window.reddit.comments("uq0mzi").sort('hot').fetch(function(res) {
res[1].data.children.flatMap((item) => {
console.log(item.data.body)
getSafe(()=>item.data.replies.data.children, []).map(y => (y.data.body === undefined ? "" : console.log(" >>>"+y.data.body)))
})})