英文:
DeepEqual treats array initialized with back tick differently?
问题
我的问题很简单，我使用反引号来初始化一个字符串数组，但我发现golang对待这个数组的方式不同：
import (
"fmt"
"reflect"
)
func main() {
x := []string{`hello world`, "me"}
y := []string{"hello", "world", "me"}
fmt.Println(x)
fmt.Println(y)
fmt.Println(reflect.DeepEqual(x, y))
}
输出结果为：
[hello world me]
[hello world me]
false
这让我感到困惑：我应该确保所有的字符串数组都以相同的方式初始化吗？
英文:
My question is quite simple, I use back tick to initiate a string array, but I found that golang treats this array differently:
import (
"fmt"
"reflect"
)
func main() {
x := []string{`hello world`, "me"}
y := []string{"hello", "world", "me"}
fmt.Println(x)
fmt.Println(y)
fmt.Println(reflect.DeepEqual(x, y))
}
The output is:
[hello world me]
[hello world me]
false
This makes me confused: should I make sure all string arrays are initiated in the same way?
答案1
得分: 5
这些是切片（slices），而不是数组（arrays），你的第一个切片有2个元素，第二个切片有3个元素，所以它们怎么可能相等呢？
尝试像这样打印它们：
fmt.Printf("%d %q\n", len(x), x)
fmt.Printf("%d %q\n", len(y), y)
输出结果：
2 ["hello world" "me"]
3 ["hello" "world" "me"]
fmt.Println()会打印传入切片的所有值，在元素之间打印一个空格。而x的第一个元素是一个字符串，它等于y的前两个元素用空格连接起来，这就是为什么你看到切片的打印内容相等。
当你使用相同的3个字符串用反引号初始化你的第一个切片时，它们将是相等的：
x = []string{`hello`, `world`, "me"}
y = []string{"hello", "world", "me"}
fmt.Printf("%d %q\n", len(x), x)
fmt.Printf("%d %q\n", len(y), y)
fmt.Println(reflect.DeepEqual(x, y))
输出结果：
3 ["hello" "world" "me"]
3 ["hello" "world" "me"]
true
在<kbd>Go Playground</kbd>上尝试一下这些代码。
英文:
Those are slices, not arrays, and your first slice has 2 elements, and the second has 3 elements, so how could they be equal?
Try printing them like this:
fmt.Printf("%d %q\n", len(x), x)
fmt.Printf("%d %q\n", len(y), y)
Output:
2 ["hello world" "me"]
3 ["hello" "world" "me"]
fmt.Prinln() will print all values of the passed slice, printing a space between elements. And first element of x is a string which equals to the first 2 elements of y joined with a space, that's why you see equal printed content for the slices.
When you use the same 3 strings to initialize your first slice with backticks, they will be equal:
x = []string{`hello`, `world`, "me"}
y = []string{"hello", "world", "me"}
fmt.Printf("%d %q\n", len(x), x)
fmt.Printf("%d %q\n", len(y), y)
fmt.Println(reflect.DeepEqual(x, y))
Output:
3 ["hello" "world" "me"]
3 ["hello" "world" "me"]
true
Try these on the <kbd>Go Playground</kbd>.
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