英文:
go has a built in "print" function?
问题
我今天遇到了一些代码，其中有一个未定义的“print”。经过一番尝试，我发现可以使用print将内容输出到控制台。
例如：
print("Hello World")
所以它似乎是一种内置函数，但我找不到任何相关的参考（而且我以为Go语言规则是小写函数从不被导入）。
这个功能是众所周知的吗？如果是的话，是否还有其他方便的函数，还是我只是非常非常困惑？
另外一点是，这个print函数不使用fmt.Printf的魔术格式化技巧（%v）。如果你打印maps或structs，你似乎会得到它们的地址。
英文:
I cam across some code today that suprised me with a 'print' that wasn't defined. After a little playing I determined that you can just use a print to get things dumped to the console
e.g.
print("Hello World")
So it seems to be some sort of builtin but I can't find any reference to it (and I thought the go rules were lowercase functions never imported anyway)
Is this well known and if so are there other convenience functions or am I just very, very confused?
One other point -- this print doesn't use the magic formatting tricks (%v) of fmt.Printf -- If you print maps or structs you seem to get their address.
答案1
得分: 13
print和println在这里被定义：http://golang.org/ref/spec#Predeclared_identifiers。
它们的目的在这里被解释：http://golang.org/ref/spec#Bootstrapping。
答案2
得分: 13
你是对的，还有其他人已经抱怨过这个问题。它已经被添加到下一个Go版本（go1.2）的内置文档中。
> 内置包
>
> 函数 print
>
> func print(args ...Type)
>
> print 内置函数以特定于实现的方式格式化其参数，并将结果写入标准错误输出。print函数对于引导和调试很有用，但不能保证会一直存在于语言中。
>
> 函数 println
>
> func println(args ...Type)
>
> println 内置函数以特定于实现的方式格式化其参数，并将结果写入标准错误输出。参数之间总是添加空格，并附加一个换行符。println函数对于引导和调试很有用，但不能保证会一直存在于语言中。
英文:
You are right, and someone else has already complained about it. It's been added to the built-in documentation for the next Go release (go1.2).
> Package builtin
>
> func print
>
> func print(args ...Type)
>
> The print built-in function formats its arguments in an
> implementation-specific way and writes the result to standard error.
> Print is useful for bootstrapping and debugging; it is not guaranteed
> to stay in the language.
>
> func println
>
> func println(args ...Type)
>
> The println built-in function formats its arguments in an
> implementation-specific way and writes the result to standard error.
> Spaces are always added between arguments and a newline is appended.
> Println is useful for bootstrapping and debugging; it is not
> guaranteed to stay in the language.
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