How to create new array from existing array with different structure

Issue

I want to reformat the existing array, how can i do it using Javascript or typescript

first array

pdfData: [
         { 
           Id: 1, 
           path:'https//path/pdf1'
         },
         { 
           Id: 1, 
           path:'https//path/pdf2'
         },
         { 
           Id: 2, 
           path:'https//path/pdf1'
         },
         { 
           Id: 2, 
           path:'https//path/pdf2'
         },
        ]

I want to convert this array to following one

data: [
        { 
           Id: 1, 
           links:['https//path/pdf1','https//path/pdf2']
         },
         { 
           Id: 2, 
           links:['https//path/pdf1','https//path/pdf2']
         },

  ]

Solution

You were asking about Typescript or Javascript - here's the Typescript version:

// Typescript version
const pdfData = [
         { 
           Id: 1, 
           path:'https//path/pdf1'
         },
         { 
           Id: 1, 
           path:'https//path/pdf2'
         },
         { 
           Id: 2, 
           path:'https//path/pdf1'
         },
         { 
           Id: 2, 
           path:'https//path/pdf2'
         },
        ]

interface TransformedDataItem {
    Id: number,
    links: string[]
}

const result = [] as TransformedDataItem[];

for (const item of pdfData) {
    const existing = result.find(it => it.Id === item.Id);    
    if (existing) {
        existing.links.push(item.path)
    } else {
        result.push({
            Id: item.Id,
            links: [item.path]
        })
    }
}

Answered By - Aadmaa