Question

因此，我正在尝试学习高阶函数，并且正在做练习等。我需要将结果返回长度小于6个字符的原始数组输入的元素。但是我认为我搞砸了语法。不知道我该如何使用高阶函数来做到这一点。帮助吗？

var courses = [calculus,cs17,litr0100,engn];

reduce(function() {
    courses.filter(courses => courses.length > 6);
    return courses;
})

Answer 1

我在做什么错了？

var courses = [calculus,cs17,litr0100,engn];
//             ^ unless these are variables this will fail
//  use let or const

reduce(function() {
// javascript does not know a reduce function
// the reducer (lambda) function has no parameters
    courses.filter(courses => courses.length > 6);
//                 ^ should be 'course' or something else then 'courses' 
//  filtering with the right syntax would've been sufficient
    return courses;
})

如此

const courses = "calculus,cs17,litr0100,engn".split(",");
const coursesFiltered = courses.filter(course => course.length > 6);
//                    ^ assign the filtered array to a different array  
//                      Array.filter doesn't mutate (change) the original
console.log(courses);
console.log(coursesFiltered);

开始学习：Array，Array.reduce，Array.filter

我在数组的高阶函数中做错了什么？ JS

1 个答案: