[Javascript + lodash] sortBy and sortedIndex

最新推荐文章于 2025-12-02 17:50:12 发布

转载最新推荐文章于 2025-12-02 17:50:12 发布 · 169 阅读

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#javascript #ViewUI

本文介绍了使用 Underscore.js 库进行数组排序的方法，包括基本字符串排序、逆序排序及根据对象属性排序，并展示了如何利用 sortedIndex 方法找到新元素在已排序数组中的正确位置。

sortBy:

var collection = ['John', 'Petteri', 'Antti', 'Joonas', 'Zhentian'];
var sorted = _.sortBy(collection);

//[ 'Antti', 'John', 'Joonas', 'Petteri', 'Zhentian' ]

var collection = ['John', 'Petteri', 'Antti', 'Joonas', 'Zhentian'];
var sorted = _.sortBy(collection).reverse();

//[ 'Zhentian', 'Petteri', 'Joonas', 'John', 'Antti' ]

var collection = [
    {age: 90, name: "Zach"},
    {age: 33,name: "Beth"},
    {age: 8,name: "Yolanda"},
    {age: 57,name: "Chris"},
    {age: 80,name: "Abe"}
];

var sorted = _.sortBy(collection, "age");

/*
[ { age: 8, name: 'Yolanda' },
  { age: 33, name: 'Beth' },
  { age: 57, name: 'Chris' },
  { age: 80, name: 'Abe' },
  { age: 90, name: 'Zach' } ]

*/

sortedIndex:

var collection = [
    {age: 90, name: "Zach"},
    {age: 33,name: "Beth"},
    {age: 8,name: "Yolanda"},
    {age: 57,name: "Chris"},
    {age: 80,name: "Abe"}
];

var newGuy = {age: 26, name: "Wan"};

var sortedCollection = _.sortBy(collection, "age");
console.log(sortedCollection);

//Want to insert an new guy, first find his a position in the array
var index = _.sortedIndex(sortedCollection, newGuy, "age");
console.log(index);  // 1

//insert into the array.
sortedCollection.splice(index, 0, newGuy);

/*
[ { age: 8, name: 'Yolanda' },
  { age: 26, name: 'Wan' },
  { age: 33, name: 'Beth' },
  { age: 57, name: 'Chris' },
  { age: 80, name: 'Abe' },
  { age: 90, name: 'Zach' } ]
*/