parameter name a of fmt package
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Delta Echo
May 25, 2021, 4:14:50 AM5/25/21
to golan...@googlegroups.com
What does the parameter name `a` stands for in fmt package's functions?
like,
func Printf(format string, a ...interface{}) (n int, err error)
Is it argument?
Jan Mercl
May 25, 2021, 5:29:49 AM5/25/21
to Delta Echo, golang-nuts
On Tue, May 25, 2021 at 10:14 AM Delta Echo <deltae...@gmail.com> wrote:
> What does the parameter name `a` stands for in fmt package's functions?
> What does the parameter name `a` stands for in fmt package's functions?
> func Printf(format string, a ...interface{}) (n int, err error)
>
> Is it argument?
It's a parameter name. ...interface{} is the type of that argument,
>
> Is it argument?
variadic in this case indicated by the ellipsis. Argument is for
example the expression 42 in fmt.Printf("%i\n", 42).
Within the body of Printf the 'a' parameter is typed as []interface{}.
These questions are best answered by checking the language
specification: https://golang.org/ref/spec#Function_types and
https://golang.org/ref/spec#Passing_arguments_to_..._parameters
Delta Echo
May 25, 2021, 6:14:24 AM5/25/21
to Jan Mercl, golang-nuts
> It's a parameter name. ...interface{} is the type of that argument,
variadic in this case indicated by the ellipsis.
You misunderstood my question.
My question was what does `a` refers to?
Like,
fd - file descriptor
ptr - pointer
peterGo
May 25, 2021, 8:36:04 AM5/25/21
to golang-nuts
The Go fmt Print functions use the C printf model for formatted output. The usual terminology is argument.
---
The C Programming Language
https://en.wikipedia.org/wiki/The_C_Programming_Language
B.1.2 Formatted Output
The printf functions provide formatted output conversion.
int fprintf(FILE *stream, const char *format, ...)
fprintf converts and writes output to stream under the control of format . The return value
is the number of characters written, or negative if an error occurred.
The format string contains two types of objects: ordinary characters, which are copied to the
output stream, and conversion specifications, each of which causes conversion and printing of
the next successive argument to fprintf.
---
POSIX
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/printf.html
NAME
printf - write formatted output
SYNOPSIS
printf format [argument...]
DESCRIPTION
The printf utility shall write formatted operands to the standard output. The argument operands shall be formatted under control of the format operand.
---
Linux
https://linux.die.net/man/1/printf
printf(1) — Linux manual page
NAME
printf - format and print data
SYNOPSIS
printf FORMAT [ARGUMENT]...
DESCRIPTION
Print ARGUMENT(s) according to FORMAT.
---
---
The C Programming Language
https://en.wikipedia.org/wiki/The_C_Programming_Language
B.1.2 Formatted Output
The printf functions provide formatted output conversion.
int fprintf(FILE *stream, const char *format, ...)
fprintf converts and writes output to stream under the control of format . The return value
is the number of characters written, or negative if an error occurred.
The format string contains two types of objects: ordinary characters, which are copied to the
output stream, and conversion specifications, each of which causes conversion and printing of
the next successive argument to fprintf.
---
POSIX
https://pubs.opengroup.org/onlinepubs/9699919799/utilities/printf.html
NAME
printf - write formatted output
SYNOPSIS
printf format [argument...]
DESCRIPTION
The printf utility shall write formatted operands to the standard output. The argument operands shall be formatted under control of the format operand.
---
Linux
https://linux.die.net/man/1/printf
printf(1) — Linux manual page
NAME
printf - format and print data
SYNOPSIS
printf FORMAT [ARGUMENT]...
DESCRIPTION
Print ARGUMENT(s) according to FORMAT.
---
Peter
tapi...@gmail.com
May 25, 2021, 9:06:27 AM5/25/21
to golang-nuts
I think it means "any" , any values.
Gyaneshwar Rao Nampally
May 25, 2021, 12:00:21 PM5/25/21
to golang-nuts
interface{} can take any kind of value,,,
as u specified above, it can take file descriptor and pointer.
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