generate fake postal code

Question

Canadian postal codes are as follow:

L5R 1Y2

I have been been playing around with lodash to pick random element from string, here is what I came up with.

num1 = _.sampleSize('ABCDEFGHIJKLMNOPQRSTUVWXYZ', 1);

char1 = _.sampleSize('123456789', 1);

num2 = _.sampleSize('ABCDEFGHIJKLMNOPQRSTUVWXYZ', 1);

char2 = _.sampleSize('123456789', 1);

num3 = _.sampleSize('ABCDEFGHIJKLMNOPQRSTUVWXYZ', 1);

char3 = _.sampleSize('123456789', 1);

char4 = _.sampleSize('ABCDEFGHIJKLMNOPQRSTUVWXYZ', 1);

console.log(char1,num1,char2 + ' ' + char3,num3,char4)

I'm not satisfied with this code, any suggestion on how I can go about optimizing it?

Check out this post https://stackoverflow.com/questions/16106701/how-to-generate-a-random-string-of-letters-and-numbers-in-javascript — hahahakebab, Aug 31 '17 at 01:56
so many repetitive steps, feels like an amateur work, or this is acceptable? what do you guys think? — Deano, Aug 31 '17 at 01:56

score 4 · Accepted Answer · answered Aug 31 '17 at 01:57

4

This is a bit shorter:

let letters = _.times(3, () => _.sample('ABCDEFGHIJKLMNOPQRSTUVWXYZ'));
let numbers = _.times(3, () => _.sample('123456789'));
console.log(`${letters[0]}${numbers[0]}${letters[1]} ${numbers[1]}${letters[2]}${numbers[2]}`);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>

answered Aug 31 '17 at 01:57

mpen

272,448
266
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Good thinking, I like es6 syntax a lot cleaner, thank you :) – Deano Aug 31 '17 at 01:58
2

For extra es6 goodness you could destructure the arrays: let [ letter1, letter2, letter3 ] = _.times(3, () => ...); – Duncan Thacker Aug 31 '17 at 02:13
I don't know Lodash, but does it maybe have some kind of zipper merge function that could combine the two arrays automatically? – nnnnnn Aug 31 '17 at 02:22
@nnnnnn It does, but we still need that space in the middle. – mpen Aug 31 '17 at 02:30

score 1 · Answer 2 · answered Aug 31 '17 at 02:37

Assuming that you can use a random int generator, to pick characters from the strings of the alphabet and digits, to arrive at two arrays:

const arrayOfLetters = ["H", "H", "H"];
const arrayOfNumbers = ["0", "0", "0"];

the concept of interleaving is actually pretty simple:

const interleave = (arr1, arr2) =>
  Array.from({ length: arr1.length }) // or use Math.min or Math.max
    .map((_, i) => [arr1[i], arr2[i]])
    .reduce((a, b) => a.concat(b), []);

interleave(arrayOfLetters, arrayOfNumbers).join(""); // H0H0H0

Interleaving an arbitrary number of arrays isn't really any harder.

The space division isn't technically part of the spec (and is also seen divided by hyphen). So if you really want to include it, or include space for it, then you can do something like:

const generateCanadianPostalCode = (separator = " ") => {
  const letters = generateLetters(3);
  const numbers = generateNumbers(3);
  const sequence = interleave(letters, numbers);
  const halves = [
    sequence.slice(0, 3).join(""),
    sequence.slice(3).join(""),
  ];
  return halves.join(separator);
};

generate fake postal code

2 Answers2