Golang Test Empty string vs len

string_test.go

package string_test

import "testing"

func Benchmark_StringNotEqual(b *testing.B) {
	z := ""
	i := 0
	for i:= 0; i<b.N; i++ {
		if z != "" {
			i++
		}
	}
	print(i)
}

func Benchmark_LenGreater(b *testing.B) {
	z := ""
	i := 0
	for i:= 0; i<b.N; i++ {
		if len(z) != 0 {
			i++
		}
	}
	print(i)
}

func Benchmark_StringEqual(b *testing.B) {
	z := ""
	i := 0
	for i:= 0; i<b.N; i++ {
		if z == "" {
			i++
		}
	}
	print(i)
}

func Benchmark_LenEqual(b *testing.B) {
	z := ""
	i := 0
	for i:= 0; i<b.N; i++ {
		if len(z) == 0 {
			i++
		}
	}
	print(i)
}



/*
	Output

	2000000000	         0.24 ns/op Benchmark_StringNotEqual
	2000000000	         0.24 ns/op Benchmark_LenGreater
	2000000000	         0.13 ns/op Benchmark_StringEqual
	2000000000	         0.14 ns/op Benchmark_LenEqual
	PASS


	As you can see there is not a lot in it, however I was surprised the time difference between == and !=  
 */

Really nice, thanks! :)

This test looks flawed to me. When the condition evaluates true you're incrementing the loop variable, thereby decreasing the number of iterations.

When you fix this, all these options perform quite similarly.