2666. Allow One Function Call.js

// 2666. Allow One Function Call
// Solved
// Easy
// Companies

// Given a function fn, return a new function that is identical to the original function except that it ensures fn is called at most once.

//     The first time the returned function is called, it should return the same result as fn.
//     Every subsequent time it is called, it should return undefined.

 

// Example 1:

// Input: fn = (a,b,c) => (a + b + c), calls = [[1,2,3],[2,3,6]]
// Output: [{"calls":1,"value":6}]
// Explanation:
// const onceFn = once(fn);
// onceFn(1, 2, 3); // 6
// onceFn(2, 3, 6); // undefined, fn was not called

// Example 2:

// Input: fn = (a,b,c) => (a * b * c), calls = [[5,7,4],[2,3,6],[4,6,8]]
// Output: [{"calls":1,"value":140}]
// Explanation:
// const onceFn = once(fn);
// onceFn(5, 7, 4); // 140
// onceFn(2, 3, 6); // undefined, fn was not called
// onceFn(4, 6, 8); // undefined, fn was not called

 

// Constraints:

//     calls is a valid JSON array
//     1 <= calls.length <= 10
//     1 <= calls[i].length <= 100
//     2 <= JSON.stringify(calls).length <= 1000

/**
 * @param {Function} fn
 * @return {Function}
 */
var once = function(fn) {
    let count = 0;
    return function(...args){
        if(count===0){
            count++;
            return fn(...args);
        }
    }
};

//need a hint :/   but i was close. i need to stop giving up 
//i thought there was some special case but there wasn't