您如何将传递给函数的任意数量的参数应用于JavaScript中另一个函数的参数？

Question

How would you apply a unlimited number of arguments to a function which is a parameter of another function?

This is what I tried:

var callIt = function(fn) {
    for(var i = 1; arguments.length + 1; i++){
        return fn(arguments[i]);
    }
 };

There is a function in the exercise which is used to convey what is being asked:

callIt(sumAll, 1);

Maybe I've had too many beers...

callIt(sumAll, 2,3) // 5 is expected but I got 2

Answer 1

Make the argument an array , remove the first element, use apply .

var callIt = function(fn) {
    var args = [].slice.call(arguments);
    return fn.apply(null, args.slice(1));
}

Or working from your code:

var callIt = function(fn) {
    var args = [];
    for(var i = 1; i < arguments.length; i++){
        args.push(arguments[i]);
    }
    return fn.apply(null, args);
};

Answer 2

function show()
        {
            var args = Array.prototype.slice.call(arguments,1);
            arguments[0](args);
        }

Answer 3

 callIt(sumAll, 2,3) // 5 is expected but I got 2 

javascript at Question return s from within for loop at first iteration. Also, for loop does not have a condition which would return false . You can utilize rest parameter to separate function parameter from remainder of parameters passed to callIt

 var callIt = function(fn, ...args) { var res = 0; for(var i = 0; i < args.length; i++){ res += fn(args[i]); } return res }; var result = callIt(function(n) { return n }, 2,3); console.log(result);