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ExtraTopLevelOperators.printfn<'T> 函数 (F#)

  • 项目

更新：2010 年 5 月

printfn 函数以给定格式打印到 stdout，并并添加新行。

命名空间/模块路径： Microsoft.FSharp.Core.ExtraTopLevelOperators

程序集：FSharp.Core（在 FSharp.Core.dll 中）

// Signature:
printfn : TextWriterFormat<'T> -> 'T

// Usage:
printfn format

参数

备注

此函数在编译的程序集中名为 PrintFormatLine。 如果从 F# 以外的语言中访问函数，或通过反射访问成员，请使用此名称。

示例

以下代码示例演示如何使用多种格式说明符的 printfn。 关于格式说明符的更多信息，请参见 Printf Module。

let isDone = false
printfn "Printing Boolean values: %b %b" isDone (not isDone)
let s1,s2 = "test1", @"C:\test2"
printfn "Printing strings (note literal printing of string with special character): %s%s" s1 s2
let i1, i2 = -123, 1891
printfn "Printing an integer in decimal form, with and without a width: %d %10d" i1 i2
printfn "Printing an integer in lowercase hexadecimal: %x or 0x%x" i1 i2
printfn "Printing as an unsigned integer: %u %u" i1 i2
printfn "Printing an integer as uppercase hexadecimal: %X or 0x%X" i1 i2
printfn "Printing as an octal integer: %o %o" i1 i2
printfn "Printing in columns."
for i in 115 .. 59 .. 1000 do
    printfn "%10d%10d%10d%10d%10d" (10100015-i) (i-100) (115+i) (99992/i) (i-8388229)
let x1, x2 = 3.141592654, 6.022E23
printfn "Printing floating point numbers %e %e" x1 x2
printfn "Printing floating point numbers %E %E" x1 x2
printfn "Printing floating point numbers %f %f" x1 x2
printfn "Printing floating point numbers %F %F" x1 x2
printfn "Printing floating point numbers %g %G" x1 x2
printfn "Using the width and precision modifiers: %10.5e %10.3e" x1 x2

printfn "Using the flags:\nZero Pad:|%010d| Plus:|%+10d |LeftJustify:|%-10d| SpacePad:|% d|" 1001 1001 1001 1001 
printfn "zero pad   | |+- both   | |- and ' ' | |' ' and 0 | | normal "
for i in -115 .. 17 .. 100 do
    printfn "|%010d| |%+-10d| |%- 10d| |% 010d| |%10d|" (80-i) (i+85) (100+i) (99992/i) (i-80)

let d = 0.124M
printfn "Decimal: %M" d

printfn "Print as object: %O %O %O %O" 12 1.1 "test" (fun x -> x + 1)

printfn "%A" [| 1; 2; 3 |]

printfn "Printing from a function (no args): %t" (fun writer -> writer.WriteLine("X"))

printfn "Printing from a function with arg: %a" (fun writer (value:int) -> writer.WriteLine("Printing {0}.", value)) 10

平台

Windows 7、Windows Vista SP2、Windows XP SP3、Windows XP x64 SP2、Windows Server 2008 R2、Windows Server 2008 SP2、Windows Server 2003 SP2

版本信息

F# 运行时

受以下版本支持：2.0、4.0

Silverlight

受以下版本支持：3

请参见

参考

Core.ExtraTopLevelOperators 模块 (F#)

Microsoft.FSharp.Core 命名空间 (F#)

修订记录

Date

修订记录

原因

2010 年 5 月

添加了代码示例。

信息补充。