如何在 javascript 数组（NodeJs）中分组（多个键）和多个属性值的总和

Question

what is most efficient way to group by(multiple key) and sum of multiple property values in javascript array

For ex -

[ 
    { Phase: "Phase 1", Step: "Step 1", Value1: "15", Value2: "5" },
    { Phase: "Phase 1", Step: "Step 2", Value1: "20", Value2: "10" },
    { Phase: "Phase 2", Step: "Step 1", Value1: "25", Value2: "15" },
    { Phase: "Phase 2", Step: "Step 2", Value1: "30", Value2: "20" },
    { Phase: "Phase 1", Step: "Step 1", Value1: "35", Value2: "25" },
    { Phase: "Phase 1", Step: "Step 2", Value1: "40", Value2: "30" },
    { Phase: "Phase 2", Step: "Step 1", Value1: "45", Value2: "35" },
    { Phase: "Phase 2", Step: "Step 2", Value1: "50", Value2: "40" }
]

Expected Output

[ 
    { Phase: "Phase 1", Step: "Step 1", Value1: "50", Value2: "30" },
    { Phase: "Phase 1", Step: "Step 2", Value1: "60", Value2: "40" },
    { Phase: "Phase 2", Step: "Step 1", Value1: "70", Value2: "50" },
    { Phase: "Phase 2", Step: "Step 2", Value1: "80", Value2: "60" }
]

Answer 1

You can do that with reduce and take Object.values of it:

 var array = [ { Phase: "Phase 1", Step: "Step 1", Value1: "15", Value2: "5" }, { Phase: "Phase 1", Step: "Step 2", Value1: "20", Value2: "10" }, { Phase: "Phase 2", Step: "Step 1", Value1: "25", Value2: "15" }, { Phase: "Phase 2", Step: "Step 2", Value1: "30", Value2: "20" }, { Phase: "Phase 1", Step: "Step 1", Value1: "35", Value2: "25" }, { Phase: "Phase 1", Step: "Step 2", Value1: "40", Value2: "30" }, { Phase: "Phase 2", Step: "Step 1", Value1: "45", Value2: "35" }, { Phase: "Phase 2", Step: "Step 2", Value1: "50", Value2: "40" }]; var result = Object.values(array.reduce((acc, {Value1, Value2,...rest})=>{ const key = Object.values(rest).join('|'); acc[key] = acc[key] || {...rest, Value1:0,Value2:0}; acc[key].Value1+=+Value1; acc[key].Value2+=+Value2; return acc; },{})); console.log(result);

Answer 2

 const data = [{Phase:"Phase 1",Step:"Step 1",Value1:"15",Value2:"5"},{Phase:"Phase 1",Step:"Step 2",Value1:"20",Value2:"10"},{Phase:"Phase 2",Step:"Step 1",Value1:"25",Value2:"15"},{Phase:"Phase 2",Step:"Step 2",Value1:"30",Value2:"20"},{Phase:"Phase 1",Step:"Step 1",Value1:"35",Value2:"25"},{Phase:"Phase 1",Step:"Step 2",Value1:"40",Value2:"30"},{Phase:"Phase 2",Step:"Step 1",Value1:"45",Value2:"35"},{Phase:"Phase 2",Step:"Step 2",Value1:"50",Value2:"40"}] const finalResult = data.reduce((result, d) => { let key = `${d.Phase}_${d.Step}`; result[key] = result[key] || {...d, Value1: 0, Value2: 0}; result[key].Value1 += +d.Value1; result[key].Value2 += +d.Value2 return result }, {}) console.log(Object.values(finalResult))