Fb Arg Extract

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FB_ARG_EXTRACT

Intrinsic define (macro) performed by the compiler.

Syntax

__FB_ARG_EXTRACT__( index, args... )

Parameters

• index
• args...

Description

Returns the argument from the argument list (args...) corresponding to the index value (index).

If the requested index value refers to an argument that does not exist in the supplied argument list (index value too large), nothing is returned.

Remarks

Differences from QB

• New to FreeBASIC

See also

• __FB_ARG_LEFTOF__
• __FB_ARG_RIGHTOF__
• __FB_ARG_COUNT__
• __Fb_Arg_Listexpand__

Examples

#print __FB_ARG_EXTRACT__( 1, 7, 89.78, "Postman" )

/' Compiler output:

89.78

'/

'   In this example, the '__FB_EVAL__' is absolutely mandatory in this 'print_last' macro,

'   because the numeric expression '__FB_ARG_COUNT__( args ) - 1' must be fully evaluated

'   before being used as the index argument of '__FB_ARG_EXTRACT__'

#macro print_last( args... )

    #define last_arg_num __FB_EVAL__( __FB_ARG_COUNT__( args ) - 1 )

    #print __FB_ARG_EXTRACT__( last_arg_num, args )

#endmacro

print_last( 7, 89.78, "Postman" )

/' Compiler output:

Postman

'/

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Category: Intrinsic Defines
Kind: keyword

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Reproduced from the FreeBASIC Wiki Manual under the GNU Free Documentation License 1.3 — with no Invariant Sections, no Front-Cover Texts and no Back-Cover Texts. Copyright © the FreeBASIC project and wiki contributors. See License.