Only in rare cases will Array.Sort perform in O(n) time. More likely, it will be O(n log n) time.
See here for more details: https://docs.microsoft.com/en-us/dotnet/api/system.array.sort?view=netframework-4.8

but you are not meeting the requirements

@Voile
IDK about JS terminology, but in C/C++ "expression" is something that has a value, so

• the first part in for (...) isn't an expression;
• var a=1,b=2,c=3 is a statement but not an expression; the only expressions here are 1, 2 and 3;
• etc.

The opening part of a for loop in JS consists of 3 expressions (separated by ;), and each statement can have multiple run-off statements in a row (separated by , instead). Since var a=1,b=2,c=3 and such is a valid (multi-statement) expression it's a valid for loop. In fact it's valid in C and other languages too: int a,b,c; for(a=1,b=2,c=3;a<10;a++); is valid and works just as intended.

Of course, putting too much stuff inside the for loop is not my style ;-) But I don't think it's that unreadable in the first place.

If you keep mentioning "is this a newb thing" twice in one comment perhaps you should just admit that you're a newbie and you're probably not qualified to give strong opinions about this.

(Yes, I'm talking about those "this is clever but not best practice" comments, they've since long become passive-aggressive assertions about "code that is short and does the task but I don't like it so I have to diss it".)

Also, this is JS, not C or Java or anything. Their syntax look similar but they're very different.

you can initialise more than one variable on a line, eg:
var a, b, c = 1, d = 5;

What about it can you not read? ~submitted from phone