How to convert imperial to metric units?

Question

This is more of a general question of both code and math. I'm not at all good at math, and I'm still learning how to apply math in programming.

Let's say, I have an object of data that has the amount, the measurement, and the type, such as feet or lb .

const data = {
  0: {
    'type': 'imperial',
    'unit': 'ft',
    'amount': 3 
  },
  1: {
    'type': 'imperial',
    'unit': 'lb',
    'amount': 5
  },
  2: {
    'type': 'imperial',
    'unit': 'mph',
    'amount': 7 
  }
}

And I need to go through this data and convert each according to the type (assuming type is what it's called)

Object.keys(data).map(key => {
    convert(data[key]['amount'], data[key]['type'], data[key]['unit'])
})

And the function converts this:

const convert = (amount, type, unit) => {
   const calc = // ???
   return calc;
}

My question is, how do I convert depending on the type of measurement? I know that 1 foot is 0.3048 meters, and if I needed to convert 5 feet to meters, I'd do 5*0.3048 .

However, how can I apply this in code, with a list of imperial and metric units and how would I add this to the convert function?

Answer 1

You can have a converter Object with functions to convert and labels to display, here's an example ( adjust the values and units to your needs ):

 const data = { 0: { type: "imperial", unit: "ft", amount: 3 }, 1: { type: "imperial", unit: "lb", amount: 5 }, 2: { type: "imperial", unit: "mph", amount: 7 } }; const converter = { imperialToMetric: { ft: val => val * 0.3048, lb: val => val * 0.453592, mph: val => val * 1.60934, labels: { ft: "meters", lb: "Kg", mph: "kmh" } }, metric: { // reverse the above } }; const result = Object.values(data).map(({ amount, type, unit }) => ({ amount: converter.imperialToMetric[unit](amount), unit: converter.imperialToMetric.labels[unit], type: "metric" })); console.log(result);