026.curry

[mewcoder]

// 实现
function curry() {}

// 测试
function sum(a, b, c) {
  return a + b + c;
}
const curriedSum = curry(sum);

console.log(curriedSum(1)(2)(3)); // 应该输出 6
console.log(curriedSum(1, 2)(3)); // 应该输出 6
console.log(curriedSum(1)(2, 3)); // 应该输出 6

[mewcoder]

// 使用递归函数调用
function curry(fn) {
    return function curried(...args) {
        if (args.length >= fn.length) {
            return fn(...args);
        }
        return (...nextArgs) => curried(...args, ...nextArgs);
    };
}

[mewcoder]

// 使用闭包
function curry(fn) {
    let len = fn.length
    let curArgs = []
    return function curried(...args) {
        curArgs.push(...args)
        if (curArgs.length >= len) {
            const res = fn(...curArgs)
            curArgs = [] // 注意要清空
            return res
        } else {
            return curried
        }
    };
};

[mewcoder]

考虑 this 绑定

function curry(fn) {
    return function curried(...args) {
        if (args.length >= fn.length) {
            return fn.apply(this, args);
        } else {
            return function (...args2) {
                return curried.apply(this, args.concat(args2));
            }
        }
    };
}

// 使用 bind
function curry(fn) {
    return function curried(...args) {
        if (args.length >= fn.length) {
            return fn.apply(this, args);
        }
        return curried.bind(this, ...args);
    };
};

[mewcoder]

不定参数

function sum(...args) {
  return args.reduce((pre, cur) => pre + cur, 0)
}

使用空参数调用触发函数 curriedSum(1)(2)(3)()

// 使用闭包
function curry(fn) {
  let allArgs = []
  return function curried(...args) {
    if (args.length === 0) {
      const res = fn(...allArgs);
      allArgs = []
      return res
    }
    allArgs.push(...args);
    return curried;
  };
};

// 递归
function curry(fn) {
    return function curried(...args) {
        return (...nextArgs) => {
            if (nextArgs.length === 0) {
                return fn(...args);
            }
            return curried(...args, ...nextArgs);
        };
    };
};

[mewcoder]

相关题目：实现 sum 的链式调用

function sum(...args) {
    const arr = [...args];

    function add(...rest) {
        arr.push(...rest);
        return add;
    }

    // 隐式调用，注意直接 console.log 不行
    add.valueOf = add.toString = function () {
        return arr.reduce((pre, cur) => pre + cur, 0)
    };

    return add;
}

console.log(+sum1(1)(2)(3)(10)(10, 20))
console.log('sum:' + sum1(1)(2)(3)(10)(10, 20))