我正在尝试获取一个 javascript 函数，它将通过使用回调方法返回一个新数组，并将一个数组和两个回调作为 arg

Question

I want to a function to accept two callbacks and return a result only if both callbacks are true:

let myMap = function(array, cb1, cb2) {
  let result = []
  for (let i = 0; i < array.length; i++) {
    let test = cb1(array[i]) && cb2(array[i])
    result.push(test)
  }

  return result
}

The desired behavior:

let triple = function (n) {
    return 3 * n;
};

let half = function (n) {
    return n / 2;
};
console.log(myMap([7, 3, 2, 9, 8], triple, half));
// [ 21, 1.5, 6, 4.5, 24 ]

Answer 1

From the desired result, it appears that you're looking to alternate the calls of the callbacks for different array elements. You're not pushing/returning only if the callback is true, you're unconditionally pushing depending on the results of one of the callbacks, which is decided on by the index.

 let myMap = function(array, cb1, cb2) { let emptyArr = [] for (let i = 0; i < array.length; i++) { let test = (i % 2 === 0? cb1: cb2)(array[i]); emptyArr.push(test); } return emptyArr } let triple = function(n) { return 3 * n; }; let half = function(n) { return n / 2; }; console.log(myMap([7, 3, 2, 9, 8], triple, half));

Or, cleaned up some

 const myMap = (array, cb1, cb2) => array.map( (val, i) => (i % 2 === 0? cb1: cb2)(val) ); const triple = n => 3 * n; const half = n => n / 2; console.log(myMap([7, 3, 2, 9, 8], triple, half));