Conditional IF statement

[pya]

Hi,

I have the foll 3 lines in a QBASIC code.

Is there a way of combining all 3 lines or at least combine into 2 lines?

IF 2^K = N GOTO 100
IF 2^K < N GOTO 110
IF 2^K > N GOTO 120

Thanx

pya

 

[mikrom]

Hi pya,
You can compute X = SGN(2 ^ K - N) + 2
which delivers results:
X = 1 when 2 ^ K < N
X = 2 when 2 ^ K = N
X = 3 when 2 ^ K > N
and then you can use for branching ON .. GOTO statement
like ON X GOTO 110, 100, 120

Here is an example which works in QB64:
on_goto.bas

[COLOR=#804040][b]CLS[/b][/color]
[COLOR=#804040][b]INPUT[/b][/color] [COLOR=#ff00ff]"K = "[/color], K
[COLOR=#804040][b]INPUT[/b][/color] [COLOR=#ff00ff]"N = "[/color], N

[COLOR=#0000ff]REM if 2 ^ K < N then X = 1[/color]
[COLOR=#0000ff]REM if 2 ^ K = N then X = 2[/color]
[COLOR=#0000ff]REM if 2 ^ K > N then X = 3[/color]
[COLOR=#0000ff]REM X = SGN(2 ^ K - N) + 2[/color]
[COLOR=#0000ff]REM PRINT "X = ", X[/color]

[COLOR=#804040][b]ON[/b][/color] [COLOR=#008080]SGN[/color]([COLOR=#ff00ff]2[/color] ^ K - N) + [COLOR=#ff00ff]2[/color] [COLOR=#804040][b]GOTO[/b][/color] less, equal, greater

less:
[COLOR=#804040][b]PRINT[/b][/color] [COLOR=#ff00ff]"2 ^ K < N"[/color]
[COLOR=#804040][b]END[/b][/color]

equal:
[COLOR=#804040][b]PRINT[/b][/color] [COLOR=#ff00ff]"2 ^ K = N"[/color]
[COLOR=#804040][b]END[/b][/color]

greater:
[COLOR=#804040][b]PRINT[/b][/color] [COLOR=#ff00ff]"2 ^ K > N"[/color]
[COLOR=#804040][b]END[/b][/color]

 

[pya]

Thanx mikrom.