deepLearn/手写Currying.html at master · wangliang1124/deepLearn · GitHub

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<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>TEST</title>
    <style>
        body {
            padding: 16px 32px;
        }

        pre {
            padding: 16px;
            line-height: 1.5;
            background-color: #f5f5f5;
        }
    </style>
</head>

<body>
    <H3>7. 实现一个JS函数柯里化</H3>
    <script>
        // 方法一
        // function currying(func) {
        //     var args = Array.prototype.slice.call(arguments, 1);
        //     return function currying() {
        //         Array.prototype.push.apply(args, arguments);
        //         if (args.length >= func.length) {
        //             return func.apply(null, args);
        //         }
        //         return currying
        //     };
        // }

        // 方法二
        // function currying(func) {
        //     var args = Array.prototype.slice.call(arguments, 1);
        //     return function currying() {
        //         Array.prototype.push.apply(args, arguments);
        //         if (arguments.length === 0) {
        //             return func.apply(null, args);
        //         }
        //         return currying;
        //     };
        // }

        // 方法三
        function currying(func) {
            var args = Array.prototype.slice.call(arguments, 1);
            return function () {
                var newArgs = args.concat([].slice.call(arguments));
                if (newArgs.length === func.length) {
                    return func.apply(this, newArgs);
                }
                newArgs.unshift(func);
                return currying.apply(this, newArgs);
            };
        }


        console.log("============== currying ==================");
        function multiFn(a, b, c) {
            return a * b * c;
        }

        var multi = currying(multiFn);
        console.log(
            multi(2, 22,4,44,4),
            multi(2)(3)(4),
            multi(2, 3, 4),
            multi(2)(3, 4),
            multi(2, 3)(4)
        );


        // 实现无限极累加 add(1)(2)(3)(4)...
        (function () {
            function addTo() {
                var sum = 0
                for (var i = 0, l = arguments.length; i < l; i++) {
                    sum += arguments[i];
                }
                return sum;
            }
            function currying(func) {
                var args = []
                const _currying = function () {
                    Array.prototype.push.apply(args, arguments)
                    // console.log(args)
                    if (arguments.length === 0) {
                        return func.apply(null, args)
                    }
                    return _currying;
                }
                // 字符类型
                _currying.toString = function () {
                    return func.apply(null, args);
                };
                // 数值类型
                _currying.valueOf = function () {
                    return func.apply(null, args);
                };

                return _currying
            }


            var add = currying(addTo)

            console.log(add(1)(3)) // ƒ 4
            console.log(add(1)(3)()) // 4
            console.log(add(1)(3).valueOf()) // 4
        }())
    </script>
</body>

</html>