When using the find method in JavaScript, the callback function should return a boolean value to determine if the item being searched for is found. It's important to remember that a truthy value indicates a match, while a falsy value means no match. Therefore, it is semantically correct to use return true. Using return comment may work because any non-null object reference is considered truthy, but it can be misleading.
Other array methods like map or sort require different types of return values from their callbacks. For example, map expects the returned value to be the item added to the mapped array, while sort expects a numerical value to determine the relative order of elements. If unsure about what the callback should return, consulting the MDN documentation or other reliable sources is recommended.
In your particular situation, ensure that the callback explicitly returns a falsy value when the ID does not match. Instead of relying on implicit undefined return, explicitly return a falsy value like so:
const comment = comments.find(function (comment) {
return comment.id === 823423;
});
A more concise approach using parameter destructuring and an arrow function would be:
const comment = comments.find(({id}) => id === 823423);