IF-THEN-ELSE-END IF
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| − | + | = <span class="f_Header">Action</span> = | |
| + | Allows conditional execution or branching, based on the evaluation of a Boolean expression. | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | = <span class="f_Header">Syntax</span> = | ||
| + | |||
| + | <span class="f_Syntax">IF</span> expression<span class="f_Syntax"> THEN</span> | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | [ <span class="f_Syntax">ELSEIF</span> expression <span class="f_Syntax">THEN</span> ] | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | [ <span class="f_Syntax">ELSE</span> ] | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | <span class="f_Syntax">END IF</span> | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | = <span class="f_Header">Remarks</span> = | ||
| + | <div style="padding: 0px; margin: 0px 0px 0px 4px;"> | ||
| + | {| width="541" cellspacing="0" cellpadding="1" border="1" style="border: 2px solid rgb(0, 0, 0); border-spacing: 0px; border-collapse: collapse;" | ||
| + | |- style="vertical-align: top;" | ||
| + | | valign="top" width="17%" style="width: 88px; border: 1px solid rgb(0, 0, 0);" | | ||
| + | Expression | ||
| + | |||
| + | | valign="top" width="100%" style="width: 444px; border: 1px solid rgb(0, 0, 0);" | | ||
| + | Any expression that evaluates to true or false. | ||
| + | |||
| + | |} | ||
| + | </div> | ||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | The one line version of IF can be used : | ||
| + | |||
| + | IF expression THEN statement [ ELSE statement ] | ||
| + | |||
| + | The use of [ELSE] is optional. | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | Tests like IF THEN can also be used with bits and bit indexes. | ||
| + | |||
| + | IF var.bit = 1 THEN | ||
| + | |||
| + | ^--- bit is a variable or numeric constant in the range from 0-255 | ||
| + | |||
| + | | ||
| + | |||
| + | You can use OR or AND to test on multiple conditions. The conditions are evaluated from left to right. | ||
| + | |||
| + | IF A=1 OR A=2 OR A=3 OR B>10 THEN | ||
| + | |||
| + | IF A=1 AND A>3 THEN | ||
| + | |||
| + | | ||
| + | |||
| + | | ||
| + | |||
| + | | ||
| + | |||
| + | Dim Var As Byte, Idx As Byte | ||
| + | |||
| + | Var = 255 | ||
| + | |||
| + | Idx = 1 | ||
| + | |||
| + | If Var.idx = 1 Then | ||
| + | |||
| + | Print "Bit 1 is 1" | ||
| + | |||
| + | EndIf | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | = <span class="f_Header">See also</span> = | ||
| + | |||
| + | [[ELSE]] | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | <span style="font-family: Arial;"> </span> | ||
| + | |||
| + | = <span class="f_Header">Example</span> = | ||
| + | |||
| + | <br/><source lang="bascomavr"> | ||
| + | Dim A As Integer | ||
| + | A = 10 | ||
| + | If A = 10 Then 'test expression | ||
| + | Print "This part is executed." 'this will be printed | ||
| + | Else | ||
| + | Print "This will never be executed." 'this not | ||
| + | End If | ||
| + | If A = 10 Then Print "New in BASCOM" | ||
| + | If A = 10 Then Goto Label1 Else print "A<>10" | ||
| + | Label1: | ||
| + | |||
| + | Rem The following example shows enhanced use of IF THEN | ||
| + | If A.15 = 1 Then 'test for bit | ||
| + | Print "BIT 15 IS SET" | ||
| + | EndIf | ||
| + | Rem the following example shows the 1 line use of IF THEN [ELSE] | ||
| + | If A.15 = 0 Then Print "BIT 15 is cleared" Else Print "BIT 15 is set" | ||
</source><br/>{{Languages}} | </source><br/>{{Languages}} | ||
[[Category:BASCOM Language Reference]] | [[Category:BASCOM Language Reference]] | ||
Latest revision as of 00:05, 21 February 2013
Contents |
Action
Allows conditional execution or branching, based on the evaluation of a Boolean expression.
Syntax
IF expression THEN
[ ELSEIF expression THEN ]
[ ELSE ]
END IF
Remarks
|
Expression |
Any expression that evaluates to true or false. |
The one line version of IF can be used :
IF expression THEN statement [ ELSE statement ]
The use of [ELSE] is optional.
Tests like IF THEN can also be used with bits and bit indexes.
IF var.bit = 1 THEN
^--- bit is a variable or numeric constant in the range from 0-255
You can use OR or AND to test on multiple conditions. The conditions are evaluated from left to right.
IF A=1 OR A=2 OR A=3 OR B>10 THEN
IF A=1 AND A>3 THEN
Dim Var As Byte, Idx As Byte
Var = 255
Idx = 1
If Var.idx = 1 Then
Print "Bit 1 is 1"
EndIf
See also
Example
Dim A As Integer A = 10 If A = 10 Then 'test expression Print "This part is executed." 'this will be printed Else Print "This will never be executed." 'this not End If If A = 10 Then Print "New in BASCOM" If A = 10 Then Goto Label1 Else print "A<>10" Label1: Rem The following example shows enhanced use of IF THEN If A.15 = 1 Then 'test for bit Print "BIT 15 IS SET" EndIf Rem the following example shows the 1 line use of IF THEN [ELSE] If A.15 = 0 Then Print "BIT 15 is cleared" Else Print "BIT 15 is set"
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