Inkey

Returns a string representing the first key waiting in the keyboard buffer

Syntax

Declare Function Inkey ( ) As String

Usage

result = Inkey[$]

Return Value

The first character found in the keyboard buffer, or an empty string ("") if none found.

Description

Peeks into the keyboard buffer and returns a String representation of the first character, if any, found. The key is then removed from the buffer, and is not echoed to the screen. If the keyboard buffer is empty, an empty string ("") is immediately returned without waiting for keys.

If the key is in the ASCII character set, a one-character String consisting of that character is returned. If the key is an "extended" one (numeric pad, cursors, functions) a two-character String is returned, the first of which is the extended character (See dialect differences below)

The Shift, Ctrl, Alt, and AltGr keys can't be read independently by this function as they never enter the keyboard buffer (although, perhaps obviously, Shift-A will be reported by Inkey differently than Control-A et cetera; Alt-A is an extended key a la the above).

See also Input() or GetKey, or Sleep to wait for a key press if the keyboard buffer is empty.

Example

Print "press q to quit" Do Sleep 1, 1 Loop Until Inkey = "q"
#if __FB_LANG__ = "qb" #define EXTCHAR Chr$(0) #else #define EXTCHAR Chr(255) #endif Dim k As String Print "Press a key, or Escape to end" Do k = Inkey$ Select Case k Case "A" To "Z", "a" To "z": Print "Letter: " & k Case "1" To "9": Print "Number: " & k Case Chr$(32): Print "Space" Case Chr$(27): Print "Escape" Case Chr$(32) To Chr$(127) Print "Printable character: " & k Case EXTCHAR & "G": Print "Up Left / Home" Case EXTCHAR & "H": Print "Up" Case EXTCHAR & "I": Print "Up Right / PgUp" Case EXTCHAR & "K": Print "Left" Case EXTCHAR & "L": Print "Center" Case EXTCHAR & "M": Print "Right" Case EXTCHAR & "O": Print "Down Left / End" Case EXTCHAR & "P": Print "Down" Case EXTCHAR & "Q": Print "Down Right / PgDn" Case EXTCHAR & Chr$(59) To EXTCHAR & Chr$(68) Print "Function key: F" & Asc(k, 2) - 58 Case EXTCHAR & Chr$(133) To EXTCHAR & Chr$(134) Print "Function key: F" & Asc(k, 2) - 122 Case Else If Len(k) = 2 Then Print Using "Extended character: chr$(###, ###)"; Asc(k, 1); Asc(k, 2) ElseIf Len(k) = 1 Then Print Using "Character chr$(###)"; Asc(k) End If End Select If k = Chr$(27) Then Exit Do Sleep 1, 1 Loop

Dialect Differences

The extended character is Chr(255) in the -lang fb and -lang fblite dialects.
- In the -lang qb dialect, the extended character depends on how the keyword is written. If the QB form Inkey$ is used, the extended character is Chr(0). If it is referenced as __Inkey, the extended char is Chr(255).
- In all other dialects, the extended char is always Chr(255).
The string type suffix $ is optional in the -lang fblite and -lang fb dialects, but required in the -lang qb dialect.

Differences from QB

None in the -lang qb dialect.
QBasic returned a Chr(0) as the first character for an extended key, but FreeBASIC returns Chr(255) as the first character in the -lang fb and -lang fblite dialects.