我们知道有两种方法可以初始化地图(如下所示).我想知道这两种方法之间是否存在任何性能差异.
- var myMap map[string]int
然后
- myMap = map[string]int{}
VS
- myMap = make(map[string]int)
在我的机器上,它们看起来大致相当.
您可以轻松地进行基准测试以进行比较.例如：
- package bench
- import "testing"
- var result map[string]int
- func BenchmarkMakeLiteral(b *testing.B) {
- var m map[string]int
- for n := 0; n < b.N; n++ {
- m = InitMapLiteral()
- }
- result = m
- }
- func BenchmarkMakeMake(b *testing.B) {
- var m map[string]int
- for n := 0; n < b.N; n++ {
- m = InitMapMake()
- }
- result = m
- }
- func InitMapLiteral() map[string]int {
- return map[string]int{}
- }
- func InitMapMake() map[string]int {
- return make(map[string]int)
- }
在3次不同的运行中产生的结果足够接近无关紧要：
第一次运行
- $go test -bench=.
- testing: warning: no tests to run
- PASS
- BenchmarkMakeLiteral-8 10000000 160 ns/op
- BenchmarkMakeMake-8 10000000 171 ns/op
- ok github.com/johnweldon/bench 3.664s
第二轮
- $go test -bench=.
- testing: warning: no tests to run
- PASS
- BenchmarkMakeLiteral-8 10000000 182 ns/op
- BenchmarkMakeMake-8 10000000 173 ns/op
- ok github.com/johnweldon/bench 3.945s
第三次运行
- $go test -bench=.
- testing: warning: no tests to run
- PASS
- BenchmarkMakeLiteral-8 10000000 170 ns/op
- BenchmarkMakeMake-8 10000000 170 ns/op
- ok github.com/johnweldon/bench 3.751s
