在 Go 中测试空字符串的最佳方法是什么？

Question

Which method is best (more idomatic) for testing non-empty strings (in Go)?

if len(mystring) > 0 { }

Or:

if mystring != "" { }

Or something else?

转载于:https://stackoverflow.com/questions/18594330/what-is-the-best-way-to-test-for-an-empty-string-in-go

Answer 1

Both styles are used within the Go's standard libraries.

if len(s) > 0 { ... }

can be found in the strconv package: http://golang.org/src/pkg/strconv/atoi.go

if s != "" { ... }

can be found in the encoding/json package: http://golang.org/src/pkg/encoding/json/encode.go

Both are idiomatic and are clear enough. It is more a matter of personal taste and about clarity.

Russ Cox writes in a golang-nuts thread:

The one that makes the code clear.
If I'm about to look at element x I typically write
len(s) > x, even for x == 0, but if I care about
"is it this specific string" I tend to write s == "".

It's reasonable to assume that a mature compiler will compile
len(s) == 0 and s == "" into the same, efficient code.
Right now 6g etc do compile s == "" into a function call
while len(s) == 0 is not, but that's been on my to-do list to fix.

Make the code clear.