pskfyi/deno-benchmarks

Deno Benchmarks

Using Deno to benchmark basic JS/TS operations.

Running

deno bench

Results

Typeof

Shockingly, it's an order of magnitude faster to use typeof x === 'string' constructing a new string each time than to use const STRING = 'string' once in the global scope then compare typeof x === STRING.

Fastest: typeof w/ new string
8.58x faster than typeof w/ const string

Array Clone

Fastest: spread
1x faster than slice
1.02x faster than concat
11.99x faster than for loop
27.04x faster than map

Has

The performance impact is negligible between using Map or Set's' has() method before set() or add() vs just using set() or add() without checking first.

Loops

Fastest: C-style for var
1.01x faster than C-style for let 
1.99x faster than for let of 
1.99x faster than for var of 
2x faster than for const of 
17.3x faster than forEach

Splitting on First Space

Using indexOf() and slice() is always at least 1 order of magnitude faster than using split() and join, and is always faster than using .match() growing to by orders of magnitude faster as the string gets longer.