This challenge sounds too simple to not already exist, so let me know if it is a duplicate.
Your code has to be in "byte order". This means that every character / byte has a higher or equal byte value than the preceding character / byte.
Exceptions to this rule are the whitespace characters, which may occur anywhere.
The usual loopholes are not allowed.
Edit: Using built-in functions / constants resolving to
Hello, world! is not allowed.
Edit 2: The output may be a(n anonymous) function returning the string, an expression resolving to the string, or any other way you think should be allowed.
HW is valid:
0x48 (H) <= 0x57 (W)
0x72 (r) > 0x69 (i)
0x50 (P) <= 0x52 (R) <= 0x69 (i) <= 0x6e (n) <= 0x74 (t)
This is code-golf so the score is the number of characters / bytes. The lower the score, the higher the ranking.