Calculation on dynamic data in React - reactjs

Question

This array can be fetched by .map in return()
[
{
"a": "3",
"Count": "3",
"b": "299.98999786376953",
"c": "30",
"d": "30"
},
{
"a": "9",
"Count": "1",
"b": "99.98999786376953",
"c": "10",
"d": "9"
}
]
I want to apply formulas on it like:
a = a/Count;
b = (b/(Count*10))*100;
c = (c/(Count*10))*100;
d = (d/(Count*10))*100;
Also find e = (a+b+c+d)/4;
then display them in each table row's data using .map
I tried npmjs.com/package/react-equation, it can do calculations directly in return() however don't fetch dynamic variables of array inside return(). I also tried creating a function outside return add(a,b){return a+b) and calling it inside return(), neither do it work and tried some other methods as well.

Answer 1

Here is a sample code that can help you continue your work. It uses map to transform your string array to float array and also return the new calculated objects
const array = [
{
"a": "3",
"Count": "3",
"b": "299.98999786376953",
"c": "30",
"d": "30"
},
{
"a": "9",
"Count": "1",
"b": "99.98999786376953",
"c": "10",
"d": "9"
}
]
const newArray = array.map(obj => {
const a = parseFloat(obj.a) / parseFloat(obj.Count);
const b = (parseFloat(obj.b)/(parseFloat(obj.Count) * 10)) * 100
const c = (parseFloat(obj.c)/(parseFloat(obj.Count) * 10)) * 100
const d = (parseFloat(obj.d)/(parseFloat(obj.Count) * 10)) * 100
return { a, b, c, d, e: (a+b+c+d)/4}
})
console.log(array, newArray)

Answer 2

I don't think you can really use map because you're doing different calculations for a and for b,c,d and for e, and also because the calcultions on a depends on value of Count. You could just define a function that accepts the entire object and performs the calculations like so:
const performCalculations = (obj) => {
obj.a = obj.a / obj.Count;
obj.b = (obj.b/(obj.Count*10))*100;
obj.c = (obj.c/(obj.Count*10))*100;
obj.d = (obj.d/(obj.Count*10))*100;
obj.e = (obj.a + obj.b + obj.c + obj.d)/4;
return obj;
}
Edit: you can use map see #Apostolos answer