什么是javascript中将字节转换为可读格式的最优雅方式

Question

I found a very elegant 'humanize' converter for Java on stackoverflow which didn't use any loops.

Is it possible to do the same with javascript? (eg 1024 bytes => 1 kb)?

As simple as it sounds I have done quite a search for it

Incase you're wondering : Java Version

Answer 1

function byteCount (bytes, unit) {
  if (bytes < (unit = unit || 1000)) 
    return bytes + " B";
  var exp = Math.floor (Math.log (bytes) / Math.log (unit));
  var pre = ' ' +(unit === 1000 ? "kMGTPE" : "KMGTPE").charAt (exp - 1) + (unit === 1000 ? "" : "i") + 'B';
    return (bytes / Math.pow (unit, exp)).toFixed (1) + pre;
}

[ 0, 27, 999, 1000, 1023, 1024, 1728, 110592, 7077888, 
  452984832, 28991029248, 1855425871872, 9223372036854775807].forEach (
    function (v) { console.log (v, byteCount (v), byteCount (v, 1024)); });

/* Displays :    
0 "0 B" "0 B"
27 "27 B" "27 B"
999 "999 B" "999 B"
1000 "1.0 kB" "1000 B"
1023 "1.0 kB" "1023 B"
1024 "1.0 kB" "1.0 KiB"
1728 "1.7 kB" "1.7 KiB"
110592 "110.6 kB" "108.0 KiB"
7077888 "7.1 MB" "6.8 MiB"
452984832 "453.0 MB" "432.0 MiB"
28991029248 "29.0 GB" "27.0 GiB"
1855425871872 "1.9 TB" "1.7 TiB"
9223372036854776000 "9.2 EB" "8.0 EiB" */

Note the Java version results table has an error displaying 7.1 KB instead of 7.1 MB

Answer 2

There's now a couple of pretty nice Humanize libraries for JS, I'd recommend you have a look at:

HubSpot/Humanize Plus

There's also https://github.com/taijinlee/humanize if you'd like to take a look.