Create a computed JSON array in JS with multiple variables-CodePudding

First off, apologies if this is normally a simple thing, but I'm not particularly experienced in JS. I'm trying to make some graphs in Plotly.js for a work site that currently holds raw JSON. We have a JSON in the format:

stuff = [{"name": "shark", "location": "somewhere", "number":10},
         {"name": "shark", "location": "somewhereelse", "number":50},
         {"name": "shark", "location": "somewhere", "number":25},
         {"name": "turtle", "location": "anotherplace", "number":1},
         {"name": "elephant", "location": "greatplace", "number":50},
         {"name": "elephant", "location": "greatplace", "number":75}

And I need the result to look like:

computed = [{"name":"shark", "location":"somewhere", "number":35},
            {"name":"shark", "location":"somewhereelse", "number":50},
            {"name":"turtle", "location":"anotherplace", "number":1},
            {"name":"elephant", "location":"greatplace", "number":125}

Where all names are grouped by location and all numbers in that group are summed. It is then this computed JSON that I'll be using to graph with Plotly.js with some functions I have already built.

I think I can simplify the problem as:

forEach((item) => {
x.push(item['location']
y.push(y  = stuff.number where stuff.location === x[-1])
}

But this also means I'll get the same number of rows as in stuff, just computed and graphed. I'm afraid I can't figure it out any further.

Any help would be muchly appreciated.

CodePudding user response：

Simply looping out the original array, and adding the elements to a new array unless they aren't added already, or just adding the number will be the trick here. Here's the defined one:

var computed: any = [];

for(var element of stuff){
  let computedElement = computed.find((ele: { location: string; }) => ele.location == element.location);
  if (computedElement){
    computedElement.number  = element.number; 
  }
  else{
    computed.push(element);
  }
}

CodePudding user response：

First of all, json starts with {} and not []. Your object is a javascript object. I did a very long function below:

const stuffList = [
{"name": "shark", "location": "somewhere", "number":10},
  {"name": "shark", "location": "somewhereelse", "number":50},
  {"name": "shark", "location": "somewhere", "number":25},
  {"name": "turtle", "location": "anotherplace", "number":1},
  {"name": "elephant", "location": "greatplace", "number":50},
  {"name": "elephant", "location": "greatplace", "number":75}
]

//extract all available location
const locations = stuffList.map( stuffItem => {
  return stuffItem.location
})

const filteredStuff = locations.map( location => {
  const number= stuffList.map( stuffItem => {
      if(stuffItem.location === location) {
        return stuffItem.number
      }
      return 0
  }).reduce( (a, b) => a   b)// total all the numbers of mathcing 
  location
  
  //get the first newStuffItem value equals to location 
  const [filteredStuffItem] = stuffList.map( stuffItem => {
    if(stuffItem.location === location) {
      return {
        name: stuffItem.name,
        location,
        number
      }
    }
  }).filter( stuffItem => {
    return stuffItem?.location === location
  })

  return filteredStuffItem
})

const newStuffList = filteredStuff.filter((thing, index) => {
  const _thing = JSON.stringify(thing);
  return index === filteredStuff.findIndex(obj => {
    return JSON.stringify(obj) === _thing;
  })
});

console.log(newStuffList)

OR the magic by Deepak in javascript:

const stuff = [
  {"name": "shark", "location": "somewhere", "number":10},
  {"name": "shark", "location": "somewhereelse", "number":50},
  {"name": "shark", "location": "somewhere", "number":25},
  {"name": "turtle", "location": "anotherplace", "number":1},
  {"name": "elephant", "location": "greatplace", "number":50},
  {"name": "elephant", "location": "greatplace", "number":75}
]

var computed = [];

for(var element of stuff){
  let computedElement = computed.find((ele) => ele.location == element.location);
  if (computedElement){
    computedElement.number  = element.number; 
  }
  else{
    computed.push(element);
  }
}

console.log(computed)