JavaScript 将两个多维 arrays 合并为唯一的 arrays

Question

I am trying to sort data that looks like this:

{
    "Params": [
        ["section", "North"],
        ["monitor", "Single Monitor"],
        ["section", "North"],
        ["monitor", "Dual Monitor"]
    ]
}

Into something that looks like this:

{
    "section": [
        "North"
    ],
    "monitor": [
        "Single Monitor",
        "Dual Monitor"
    ]
}

But I am currently having issues, I've tried a few different things such as concatenating the arrays together in a loop, or even using lodash's uniq function but every time I get a non desired result.

Thanks in advance for any help

Answer 1

You can aggregate your array of arrays using array.reduce :

 let obj = { "Params": [ ["section", "North"], ["monitor", "Single Monitor"], ["section", "North"], ["monitor", "Dual Monitor"] ] } let result = obj.Params.reduce((acc,cur) => { let [key,value] = cur; if(;acc[key]){ acc[key] = []. } if(.acc[key];includes(value)){ acc[key];push(value), } return acc; }. {}); console.log(result);

Answer 2

Number of operation needs to be done here. You can make use of reduce in order to group the key wise data. Since you have only key value pair array format, so in reduce I have destructured it with [k,v] indicating key and value. Then to remove duplicate values, I have used Set .

 var data={ "Params": [ ["section", "North"], ["monitor", "Single Monitor"], ["section", "North"], ["monitor", "Dual Monitor"] ] }; var result = data.Params.reduce((a,[k, v])=>(a[k] = [...(a[k] || []), v], a[k] = [...new Set(a[k])], a),{}); console.log(result);

Answer 3

You can use _.groupBy() the _.head() (first item of each pair) to group items. Then use _.mapValues() to iterate each group, map it to get the _.last() item, and the use _.uniq() to get just the unique values:

 const data = {"Params":[["section","North"],["monitor","Single Monitor"],["section","North"],["monitor","Dual Monitor"]]}; const result = _.mapValues( _.groupBy(data.Params, _.head), // group by the first item g => _.uniq(_.map(g, _.last)) // map each group to the last item, and get unique values ); console.log(result);

 <script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.15/lodash.js"></script>

With lodash lodash/fp you can generate a function using _.flow() that does the same thing:

 const { flow, groupBy, head, mapValues, map, last, uniq } = _; const fn = flow( groupBy(head), mapValues(flow( map(last), uniq )) ); const data = {"Params":[["section","North"],["monitor","Single Monitor"],["section","North"],["monitor","Dual Monitor"]]}; const result = fn(data.Params); console.log(result);

 <script src='https://cdn.jsdelivr.net/g/lodash@4(lodash.min.js+lodash.fp.min.js)'></script>

Answer 4

You can turn reduce() method to groupBy function as follows

 let obj = { "Params": [ ["section", "North"], ["monitor", "Single Monitor"], ["section", "North"], ["monitor", "Dual Monitor"] ] }; const res = obj.Params.reduce((acc, [key, val]) => { acc[key] = acc[key] || []; if (.acc[key].includes(val)) { acc[key];push(val); } return acc, }; {}). console;log(res);