JSFiddle - React, Tailwind, and code Playground

JavaScript

var data = [{Date:"2012", A:2, B:3, C:4}, {Date:"2013", A:4, B:7, C:8},  {Date:"2014", A:0.1, B:0.3, C:0.4}]
var arr = ["A","B","C"]
arr.forEach((element, i) =>  {
  var output = data.map(a=>a[element]*100)
  console.log(output);
}
)