How to get bytes of a String in Dart?

Question

How can I read the bytes of a String in dart? in Java it is possible through the String method getBytes().

See example

Solution 1

import 'dart:convert';

String foo = 'Hello world';
List<int> bytes = utf8.encode(foo);
print(bytes);

Output: [72, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]

Also, if you want to convert back:

String bar = utf8.decode(bytes);

Solution 2

There is a codeUnits getter that returns UTF-16

String foo = 'Hello world';
List<int> bytes = foo.codeUnits;
print(bytes);

[72, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]

and runes that returns Unicode code-points

String foo = 'Hello world';
// Runes runes = foo.runes;
// or
Iterable<int> bytes = foo.runes;
print(bytes.toList());

[72, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100]

Solution 3

For images they might be base64 encoded, use

Image.memory(base64.decode('base64EncodedImageString')),

import function from

import 'dart:convert';

Comments

[Günter Zöchbauer]

Yup the differences will only show when you use multi-byte characters, but I don't know your use case and I don't know what getBytes() does exactly. I thought alternative options would at least be interesting to know ;-)

[gyorgio88]

I just tried utf8.encode() of the package 'dart:convert' and I get the desired result..E.G: print("哔".runes.length) return -> 1 byte, instead print(utf8.encode("哔").length) return -> 3 byte

[Günter Zöchbauer]

utf8.encode() returns individual bytes [229, 147, 148], my variants return [21716]. Is this what you actually wanted because you accepted my answer?

[gyorgio88]

sorry, i'm wrong ... yours is a alternative options for other contexts. thanks :)

[JChen___]

nice! but remember add import 'dart:convert';