Merge pull request #450 from atomiks/prettyBytes

[FEATURE] Add prettyBytes snippet

snippets/prettyBytes.md

@@ -0,0 +1,28 @@
+### prettyBytes
+
+Converts a number in bytes to a human-readable string.
+
+Use an array dictionary of units to be accessed based on the exponent. 
+Use `Number.toPrecision()` to truncate the number to a certain number of digits. 
+Return the prettified string by building it up, taking into account the supplied options and whether it is negative or not.
+Omit the second argument, `precision`, to use a default precision of `3` digits.
+Omit the third argument, `addSpace`, to add space between the number and unit by default.
+
+```js
+const prettyBytes = (num,  precision = 3, addSpace = true) => {
+  const UNITS = ['B','KB','MB','GB','TB','PB','EB','ZB','YB'];
+  if (Math.abs(num) < 1) return num + (addSpace ? ' ' : '') + UNITS[0];
+  const exponent = Math.min(Math.floor(Math.log10(num < 0 ? -num : num) / 3), UNITS.length - 1);
+  const n = Number(((num < 0 ? -num : num) / 1000 ** exponent).toPrecision(precision));
+  return ((num < 0 ? '-' : '') + n + (addSpace ? ' ' : '') + UNITS[exponent]);
+};
+```
+
+```js
+prettyBytes(1000); // 1 KB
+prettyBytes(123456789); // 123 MB
+prettyBytes(-50); // -50 B
+prettyBytes(27145424323.5821); // 27.1 GB
+prettyBytes(27145424323.5821, 5 ); // 27.145 GB
+prettyBytes(5500, 3, false); // 5.5KB
+```