LeetCode #2666: Allow One Function
β’ 89 words β’ 1 min
LeetCode #2666: Allow One Function:
Closure:
typescript
type JSONValue = null | boolean | number | string | JSONValue[] | { [key: string]: JSONValue };
type OnceFn = (...args: JSONValue[]) => JSONValue | undefined
function once(fn: Function): OnceFn {
let called = false;
return function (...args) {
if (!called) {
called = true;
return fn(...args);
}
};
}
/**
* let fn = (a,b,c) => (a + b + c)
* let onceFn = once(fn)
*
* onceFn(1,2,3); // 6
* onceFn(2,3,6); // returns undefined without calling fn
*/