number_precision.js

/**
 * An idea how to address this 'issue'
 * js> 0.1+0.2==0.3
 *  false
 * 
 * The problem here is that number does not always equal to what is displayed
 * js> (0.1).toPrecision(21)
 * 0.100000000000000005551
 * js> (0.2).toPrecision(21)
 * 0.200000000000000011102
 * js> (0.1+0.2).toPrecision(21)
 * 0.300000000000000044409
 */

// Identify the minimum required precision
const precision = 8

const num1 = 0.1
const num2 = 0.2
const num3 = 0.3

// use setter and getter to 'format'/'cast' numbers acccordingly when saving and reading the values

console.log(
  Number.parseFloat(
    (
      Number.parseFloat( (num1).toPrecision(precision)  ) // a number
      +
      Number.parseFloat( (num2).toPrecision(precision)  ) // another number
    ).toPrecision(precision)
  )
  ===
  Number.parseFloat( (num3).toPrecision(precision) ) // resulted number
) // true