JSON data calculation and re-formate using Angular - json

Question

I have a JSON file and I am trying to calculate the JSON file key based on the value and reformating it. My JSON file looks like below:
data=[
{
pet:'Cat',
fruit:'Apple',
fish:'Hilsha'
},
{
pet:'Dog',
fish:'Carp'
},
{
pet:'Cat',
fruit:'Orange',
fish:'Lobster'
}
];
I do like to calculate and formate it like below:
data=[
{
label:'Pet',
total:3,
list:[
{
name:'Cat',
value: 2,
},
{
name:'Dog',
value: 1,
}
]
},
{
label:'Fruit',
total:2,
list:[
{
name:'Apple',
value: 1,
},
{
name:'Orange',
value: 1,
}
]
},
{
label:'Fish',
total:3,
list:[
{
name:'Hilsha',
value: 1,
},
{
name:'Carp',
value: 1,
},
{
name:'Lobster',
value: 1,
}
]
},
];
If anybody can help me, it will be very help for me and will save a day.

Answer 1

I have fixed this task myself. If I have any wrong, you can put your comment fill-free :)
``
ngOnInit(): void {
this.dataService.$data.subscribe(data => {
// Create new object and calculation according to category
let petObj: any = {}
let fruitObj: any = {}
let fishObj: any = {}
data.forEach((el: any) => {
if (el.pet != undefined) {
petObj[el.pet] = (petObj[el.pet] || 0) + 1;
}
if (el.fruit != undefined) {
fruitObj[el.fruit] = (fruitObj[el.fruit] || 0) + 1;
}
if (el.fish != undefined) {
fishObj[el.fish] = (fishObj[el.fish] || 0) + 1;
}
});
// Create list according to category
let pet_list: any = [];
let fruit_list: any = [];
let fish_list: any = [];
for (var key in petObj) {
let pet = {
label: key,
value: petObj[key]
}
pet_list.push(pet)
}
for (var key in fruitObj) {
let fruit = {
label: key,
value: fruitObj[key]
}
fruit_list.push(fruit)
}
for (var key in fishObj) {
let fish = {
label: key,
value: fishObj[key]
}
fish_list.push(fish)
}
// Calculate total sum according to category
var totalPet = pet_list.map((res: any) => res.value).reduce((a: any, b: any) => a + b);
var totalFruit = fruit_list.map((res: any) => res.value).reduce((a: any, b: any) => a + b);
var totalFish = fish_list.map((res: any) => res.value).reduce((a: any, b: any) => a + b);
// Rearrange the JSON
this.rearrangeData = [
{
label: 'Pet',
total: totalPet,
list: pet_list
},
{
label: 'Fruit',
total: totalFruit,
list: fruit_list
},
{
label: 'Fish',
total: totalFish,
list: fish_list
}
]
console.log(this.rearrangeData)
// End rearrange the JSON
});
}
``

Answer 2

You can simplify your function. Take a look this one
group(oldData) {
const data = []; //declare an empty array
oldData.forEach((x) => {
//x will be {pet: 'Cat',fruit: 'Apple',fish: 'Hilsha'},
// {pet: 'Dog',fish: 'Carp'}
// ...
Object.keys(x).forEach((key) => {
//key will be 'pet','fruit',...
const item = data.find((d) => d.label == key); //search in the "data array"
if (item) { //if find it
item.total++; //add 1 to the property total of the element find it
// and search in the item.list the 'Cat'
const list = item.list.find((l) => l.name == x[key]);
//if find it add 1 to the property value of the list
if (list)
list.value++;
else
//if not, add to the list
//an object with property "name" and "value" equal 1
item.list.push({ name: x[key], value: 1 });
} else
//if the element is not in the "array data"
//add an object with properties label, total and list
//see that list is an array with an unique element
data.push({
label: key,
total: 1,
list: [{ name: x[key], value: 1 }],
});
});
});
return data;
}
You can use like
this.dataService.$data.subscribe(data => {
this.rearrangeData=this.group(data)
}
NOTE: this function the labels are 'pet','fruit' and 'fish' not 'Pet', 'Fruit' and 'Fish'

Answer 3

Did you try reading the text leading up to this exercise? That'd be my first approach. After that, I'd use reduce. You can do pretty much anything with reduce.