CODEWITHSUNDEEP
javascriptarraysendianness
Zach Gates
Zach Gates

Reputation: 4130

Packing binary data in JavaScript

If I have unpacked binary data

1700885369 # translates to 'easy'

How can I get back to a byte array (most preferably without importing anything)? Like Python's struct.Struct(format).pack:

>>> import struct
>>> s = struct.Struct('>1I') # a big-endian, two-byte, unsigned int
>>> s.pack(1700885369)
b'easy' # bytearray([101, 97, 115, 121])

Upvotes: 1

Views: 594

Answers (1)

Guffa
Guffa

Reputation: 700322

You can get a byte at a time from the value and put in an array:

var value = 1700885369;
var arr = [];
while (value > 0) {
  arr.unshift(value % 256);
  value = Math.floor(value / 256);
}

// display value in StackOverflow snippet
document.write(arr);

Upvotes: 1

Related Questions