Performance deep dive

In this approach, we'll find out how to most efficiently determine if a string is an Pangram in Go.

The approaches page lists two idiomatic approaches to this exercise:

1. Using strings.ContainsRune().
2. Using a bit field.

Benchmarks

To benchmark the approaches, we ran the following Benchmark code for each approach:

func BenchmarkPangram(b *testing.B) {
	for i := 0; i < b.N; i++ {
		for _, test := range testCases {
			IsPangram(test.input)
		}
	}
}

and received the following results:

bit field
BenchmarkPangram-12    	 6435968	       164.8 ns/op	       0 B/op	       0 allocs/op

strings.ContainsRune()
BenchmarkPangram-12    	  707517	      1723 ns/op	      96 B/op	       2 allocs/op

Generally, the fewer bytes allocated per op (B/op) the faster (i.e. the fewer ns/op) the implementation. More info on reading benchmarks can be found here.

The fastest is the Bit feld approach.