Array of [key, value] pairs that adhere to the specified types.
The value type V is the first specifiable generic because in most cases, you're
using a string for the key (which is what is used for the second generic K
as the default).
enum SomeKey { A = "a", B = "b", C = "c" };
const dict: Record<SomeKey, number> = {
[SomeKey.A]: 1,
[SomeKey.B]: 2,
[SomeKey.C]: 3,
};
const untypedEntries = Object.entries(dict);
for (const [key, value] of untypedEntries) {
// This will throw a TypeScript error:
console.log(dict[key]);
}
const typedEntries = entriesOf<number, SomeKey>(dict);
for (const [key, value] of typedEntries) {
// This will *not* throw a TypeScript error:
console.log(dict[key]);
}
Creates an array of [key, value] pairs for the specified
dict. The purpose of this function is to allow an override for the type of the object key since TypeScript defaults to only allowing a string, number, or symbol (but it could be an enum).Only use this function when you know that the return value of
Object.entrieswill always correspond to the keys/values of the specified object and doesn't contain any extra keys/values (which is probably the case most of the time if you're using plain JS objects).