如果我有一个JavaScript对象,如:
var list = {
"you": 100,
"me": 75,
"foo": 116,
"bar": 15
};
是否有一种方法可以根据值对属性进行排序?最后得到
list = {
"bar": 15,
"me": 75,
"you": 100,
"foo": 116
};
如果我有一个JavaScript对象,如:
var list = {
"you": 100,
"me": 75,
"foo": 116,
"bar": 15
};
是否有一种方法可以根据值对属性进行排序?最后得到
list = {
"bar": 15,
"me": 75,
"you": 100,
"foo": 116
};
当前回答
打印稿
下面的函数根据值或值的属性对对象进行排序。如果你不使用TypeScript,你可以删除类型信息,将其转换为JavaScript。
/**
* Represents an associative array of a same type.
*/
interface Dictionary<T> {
[key: string]: T;
}
/**
* Sorts an object (dictionary) by value or property of value and returns
* the sorted result as a Map object to preserve the sort order.
*/
function sort<TValue>(
obj: Dictionary<TValue>,
valSelector: (val: TValue) => number | string,
) {
const sortedEntries = Object.entries(obj)
.sort((a, b) =>
valSelector(a[1]) > valSelector(b[1]) ? 1 :
valSelector(a[1]) < valSelector(b[1]) ? -1 : 0);
return new Map(sortedEntries);
}
使用
var list = {
"one": { height: 100, weight: 15 },
"two": { height: 75, weight: 12 },
"three": { height: 116, weight: 9 },
"four": { height: 15, weight: 10 },
};
var sortedMap = sort(list, val => val.height);
JavaScript对象中键的顺序是不保证的,所以我将排序并将结果返回为一个保留排序顺序的Map对象。
如果你想把它转换回Object,你可以这样做:
var sortedObj = {} as any;
sortedMap.forEach((v,k) => { sortedObj[k] = v });
其他回答
我为此做了一个插件,它接受1个arg,这是一个未排序的对象,并返回一个对象,已排序的道具值。这将适用于所有二维对象,如{"Nick": 28, "Bob": 52}…
var sloppyObj = {
'C': 78,
'A': 3,
'B': 4
};
// Extend object to support sort method
function sortObj(obj) {
"use strict";
function Obj2Array(obj) {
var newObj = [];
for (var key in obj) {
if (!obj.hasOwnProperty(key)) return;
var value = [key, obj[key]];
newObj.push(value);
}
return newObj;
}
var sortedArray = Obj2Array(obj).sort(function(a, b) {
if (a[1] < b[1]) return -1;
if (a[1] > b[1]) return 1;
return 0;
});
function recreateSortedObject(targ) {
var sortedObj = {};
for (var i = 0; i < targ.length; i++) {
sortedObj[targ[i][0]] = targ[i][1];
}
return sortedObj;
}
return recreateSortedObject(sortedArray);
}
var sortedObj = sortObj(sloppyObj);
alert(JSON.stringify(sortedObj));
下面是该函数按预期工作的演示 http://codepen.io/nicholasabrams/pen/RWRqve?editors=001
function sortObjByValue(list){
var sortedObj = {}
Object.keys(list)
.map(key => [key, list[key]])
.sort((a,b) => a[1] > b[1] ? 1 : a[1] < b[1] ? -1 : 0)
.forEach(data => sortedObj[data[0]] = data[1]);
return sortedObj;
}
sortObjByValue(list);
Github Gist Link
以防万一,有人正在寻找保持对象(键和值),使用@Markus R和@James Moran注释的代码引用,只需使用:
var list = {"you": 100, "me": 75, "foo": 116, "bar": 15};
var newO = {};
Object.keys(list).sort(function(a,b){return list[a]-list[b]})
.map(key => newO[key] = list[key]);
console.log(newO); // {bar: 15, me: 75, you: 100, foo: 116}
这可能是一种将其作为真实有序对象处理的简单方法。不知道它有多慢。也可能更好的while循环。
Object.sortByKeys = function(myObj){
var keys = Object.keys(myObj)
keys.sort()
var sortedObject = Object()
for(i in keys){
key = keys[i]
sortedObject[key]=myObj[key]
}
return sortedObject
}
然后我找到了这个逆函数 http://nelsonwells.net/2011/10/swap-object-key-and-values-in-javascript/
Object.invert = function (obj) {
var new_obj = {};
for (var prop in obj) {
if(obj.hasOwnProperty(prop)) {
new_obj[obj[prop]] = prop;
}
}
return new_obj;
};
So
var list = {"you": 100, "me": 75, "foo": 116, "bar": 15};
var invertedList = Object.invert(list)
var invertedOrderedList = Object.sortByKeys(invertedList)
var orderedList = Object.invert(invertedOrderedList)
如果我有一个这样的对象,
var dayObj = {
"Friday":["5:00pm to 12:00am"] ,
"Wednesday":["5:00pm to 11:00pm"],
"Sunday":["11:00am to 11:00pm"],
"Thursday":["5:00pm to 11:00pm"],
"Saturday":["11:00am to 12:00am"]
}
我想按天排序,
我们应该先有daySorterMap,
var daySorterMap = {
// "sunday": 0, // << if sunday is first day of week
"Monday": 1,
"Tuesday": 2,
"Wednesday": 3,
"Thursday": 4,
"Friday": 5,
"Saturday": 6,
"Sunday": 7
}
初始化一个单独的对象sortedDayObj,
var sortedDayObj={};
Object.keys(dayObj)
.sort((a,b) => daySorterMap[a] - daySorterMap[b])
.forEach(value=>sortedDayObj[value]= dayObj[value])
你可以返回sortedDayObj