[Javascript] Array methods in depth - filter-优快云博客

本文介绍如何使用JavaScript中的数组方法如filter、sort等来筛选和排序数组元素。通过一个具体的例子展示了如何根据条件筛选出特定的数组元素，并按特定标准进行排序。

Array filter creates a new array with all elements that pass the test implemented by the provided function. In this lesson we discuss how only a truthy or falsey value is required as the return value to the function, which in turns allows us to be creative in how we perform the filter. We end the lesson by looking at an example showing how chaining multiple array methods together can lead to very nice, declarative code.

const lessons = [
    {
        title: 'Javascript Arrays in Depth - join',
        views: 960,
        tags: ['array', 'join']
    },
    {
        title: 'Javascript Arrays in Depth - concat',
        views: 1050,
        tags: ['array', 'concat']
    },
    {
        title: 'Javascript Arrays in Depth - slice',
        views: 2503,
        tags: ['array', 'slice']
    },
    {
        title: 'Javascript Functions in Depth - bind',
        views: 2500,
        tags: ['functions', 'bind']
    }
];

const minViews = 1000;
const searchTerm = 'array';

const filtered = lessons
    .filter(x => x.tags.indexOf(searchTerm) > -1)
    .filter(x => x.views > minViews)
    .sort((a, b) => b.views - a.views)
    .map(x => `  <li>${x.title}</li>`)
    .join('\n');

console.log(`<ul>
${filtered}
</ul>`);