getting the response from express api how can change the array data like this thanks in advance help me !

input = [
    { secId: "12", stuName: "aaa", stuGrade: "A", stuTotal: 100 },
    { secId: "12", stuName: "bbb", stuGrade: "A ", stuTotal: 98 },
    { secId: "13", stuName: "ccc", stuGrade: "B", stuTotal: 95 },
    { secId: "13", stuName: "ddd", stuGrade: "A", stuTotal: 70 },
  ];

output = [
    {
      secId: 12,
      stuDetails: [
        { stuName: "aaa", stuGrade: "A", stuTotal: 100 },
        { stuName: "bbb", stuGrade: "A ", stuTotal: 98 },
      ],
    },
    {
      secId: 13,
      stuDetails: [
        { stuName: "ccc", stuGrade: "B", stuTotal: 95 },
        { stuName: "ddd", stuGrade: "A", stuTotal: 70 },
      ],
    },
  ];

CodePudding user response：

use reduce

const input = [
    { secId: "12", stuName: "aaa", stuGrade: "A", stuTotal: 100 },
    { secId: "12", stuName: "bbb", stuGrade: "A ", stuTotal: 98 },
    { secId: "13", stuName: "ccc", stuGrade: "B", stuTotal: 95 },
    { secId: "13", stuName: "ddd", stuGrade: "A", stuTotal: 70 },
  ];
  
  
  const result = input.reduce((acc,item) => {
    const existingInput = acc.find(i => i.secId === item.secId)
    
    if(existingInput){
      existingInput.stuDetails.push({stuName: item.stuName, stuGrade: item.stuGrade, stuTotal: item.tuTotal })
      
    }
    else{
      acc.push({secId: item.secId, stuDetails: [{stuName: item.stuName, stuGrade: item.stuGrade, stuTotal: item.tuTotal }]})
      
   
    }
    
      return acc
   
  }, [])
  
  console.log(result)

CodePudding user response：

We can do it via Array.reduce()

let input = [
    { secId: "12", stuName: "aaa", stuGrade: "A", stuTotal: 100 },
    { secId: "12", stuName: "bbb", stuGrade: "A ", stuTotal: 98 },
    { secId: "13", stuName: "ccc", stuGrade: "B", stuTotal: 95 },
    { secId: "13", stuName: "ddd", stuGrade: "A", stuTotal: 70 },
  ];
  
let output = input.reduce((a,v) => {
   let {secId,...item} = v
   let obj = a.find(i => i.secId === secId)
   if(obj){
     obj.stuDetails.push(item)
   }else{
     a.push({'secId':secId,'stuDetails':[item]})
   }
   return a
},[])
console.log(output)