从这个最初的问题,我将如何在多个字段应用排序?
使用这种稍作调整的结构,我将如何排序城市(上升)和价格(下降)?
var homes = [
{"h_id":"3",
"city":"Dallas",
"state":"TX",
"zip":"75201",
"price":"162500"},
{"h_id":"4",
"city":"Bevery Hills",
"state":"CA",
"zip":"90210",
"price":"319250"},
{"h_id":"6",
"city":"Dallas",
"state":"TX",
"zip":"75000",
"price":"556699"},
{"h_id":"5",
"city":"New York",
"state":"NY",
"zip":"00010",
"price":"962500"}
];
我喜欢的事实是,给出的答案提供了一个一般的方法。在我计划使用这段代码的地方,我将不得不对日期以及其他东西进行排序。“启动”对象的能力似乎很方便,如果不是有点麻烦的话。
我试图把这个答案构建成一个很好的通用示例,但我运气不太好。
另一种方式
var homes = [
{"h_id":"3",
"city":"Dallas",
"state":"TX",
"zip":"75201",
"price":"162500"},
{"h_id":"4",
"city":"Bevery Hills",
"state":"CA",
"zip":"90210",
"price":"319250"},
{"h_id":"6",
"city":"Dallas",
"state":"TX",
"zip":"75000",
"price":"556699"},
{"h_id":"5",
"city":"New York",
"state":"NY",
"zip":"00010",
"price":"962500"}
];
function sortBy(ar) {
return ar.sort((a, b) => a.city === b.city ?
b.price.toString().localeCompare(a.price) :
a.city.toString().localeCompare(b.city));
}
console.log(sortBy(homes));
这是一个递归算法,按多个字段排序,同时有机会在比较之前格式化值。
var data = [
{
"id": 1,
"ship": null,
"product": "Orange",
"quantity": 7,
"price": 92.08,
"discount": 0
},
{
"id": 2,
"ship": "2017-06-14T23:00:00.000Z".toDate(),
"product": "Apple",
"quantity": 22,
"price": 184.16,
"discount": 0
},
...
]
var sorts = ["product", "quantity", "ship"]
// comp_val formats values and protects against comparing nulls/undefines
// type() just returns the variable constructor
// String.lower just converts the string to lowercase.
// String.toDate custom fn to convert strings to Date
function comp_val(value){
if (value==null || value==undefined) return null
var cls = type(value)
switch (cls){
case String:
return value.lower()
}
return value
}
function compare(a, b, i){
i = i || 0
var prop = sorts[i]
var va = comp_val(a[prop])
var vb = comp_val(b[prop])
// handle what to do when both or any values are null
if (va == null || vb == null) return true
if ((i < sorts.length-1) && (va == vb)) {
return compare(a, b, i+1)
}
return va > vb
}
var d = data.sort(compare);
console.log(d);
如果a和b相等,它将尝试下一个字段,直到没有可用字段。
改编自@chriskelly的回答。
大多数答案都忽略了,如果价值在1万美元以下或超过100万美元,价格将无法正确排序。原因是JS按字母顺序排序。这里回答得很好,为什么JavaScript不能对“5,10,1”排序,这里如何正确地对整数数组排序。
最后,如果我们要排序的字段或节点是一个数字,我们必须做一些计算。我并不是说在这种情况下使用parseInt()是正确的答案,排序结果更重要。
var homes = [{
"h_id": "2",
"city": "Dallas",
"state": "TX",
"zip": "75201",
"price": "62500"
}, {
"h_id": "1",
"city": "Dallas",
"state": "TX",
"zip": "75201",
"price": "62510"
}, {
"h_id": "3",
"city": "Dallas",
"state": "TX",
"zip": "75201",
"price": "162500"
}, {
"h_id": "4",
"city": "Bevery Hills",
"state": "CA",
"zip": "90210",
"price": "319250"
}, {
"h_id": "6",
"city": "Dallas",
"state": "TX",
"zip": "75000",
"price": "556699"
}, {
"h_id": "5",
"city": "New York",
"state": "NY",
"zip": "00010",
"price": "962500"
}];
homes.sort(fieldSorter(['price']));
// homes.sort(fieldSorter(['zip', '-state', 'price'])); // alternative
function fieldSorter(fields) {
return function(a, b) {
return fields
.map(function(o) {
var dir = 1;
if (o[0] === '-') {
dir = -1;
o = o.substring(1);
}
if (!parseInt(a[o]) && !parseInt(b[o])) {
if (a[o] > b[o]) return dir;
if (a[o] < b[o]) return -(dir);
return 0;
} else {
return dir > 0 ? a[o] - b[o] : b[o] - a[o];
}
})
.reduce(function firstNonZeroValue(p, n) {
return p ? p : n;
}, 0);
};
}
document.getElementById("output").innerHTML = '<pre>' + JSON.stringify(homes, null, '\t') + '</pre>';
<div id="output">
</div>
用来测试的小提琴
您可以使用lodash或derby函数lodash
它有两个参数字段数组和方向数组('asc','desc')
var homes = [
{"h_id":"3",
"city":"Dallas",
"state":"TX",
"zip":"75201",
"price":"162500"},
{"h_id":"4",
"city":"Bevery Hills",
"state":"CA",
"zip":"90210",
"price":"319250"},
{"h_id":"6",
"city":"Dallas",
"state":"TX",
"zip":"75000",
"price":"556699"},
{"h_id":"5",
"city":"New York",
"state":"NY",
"zip":"00010",
"price":"962500"}
];
var sorted =. data._.orderBy(data, ['city', 'price'], ['asc','desc'])
为了简化操作,可以使用这些辅助函数。
您可以根据需要对任意多个字段进行排序。对于每个排序字段,指定属性名,然后可选地指定-1作为排序方向,以降序排序而不是升序排序。
const data = [
{"h_id":"3","city":"Dallas","state":"TX","zip":"75201","price":"162500"},
{"h_id":"4","city":"Bevery Hills","state":"CA","zip":"90210","price":"319250"},
{"h_id":"6","city":"Dallas","state":"TX","zip":"75000","price":"556699"},
{"h_id":"5","city":"New York","state":"NY","zip":"00010","price":"962500"},
{"h_id":"7","city":"New York","state":"NY","zip":"00010","price":"800500"}
]
const sortLexically = (p,d=1)=>(a,b)=>d * a[p].localeCompare(b[p])
const sortNumerically = (p,d=1)=>(a,b)=>d * (a[p]-b[p])
const sortBy = sorts=>(a,b)=>sorts.reduce((r,s)=>r||s(a,b),0)
// sort first by city, then by price descending
data.sort(sortBy([sortLexically('city'), sortNumerically('price', -1)]))
console.log(data)