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ifthenelse [2019/06/09 08:27] – neilsifthenelse [2019/07/15 10:17] (current) – neils
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 Syntax: Syntax:
  
- if <any relation> [and | or <any relation>] then <statements> [else <statements>]+  if <any relation> [and | or <any relation>] then <statements> [else <statements>]
   
 +or, since version 2.1:
 +
 +  if <any relation> [and | or <any relation>] then
 +    <statements>
 +  [else
 +    <statements>]
 +  endif
 +
 Conditional structure. Executes the statements after ''THEN'' if the expression evaluates to true, otherwise the statements after ''ELSE'', if present. ''ELSE'' is optional. Conditional structure. Executes the statements after ''THEN'' if the expression evaluates to true, otherwise the statements after ''ELSE'', if present. ''ELSE'' is optional.
  
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 Please refer to the [[operators|Operators]] page for the list of supported operators. Please refer to the [[operators|Operators]] page for the list of supported operators.
- 
-Since version 1.2, multiple statements can be written in one line using the statement separator character ('':''). This, in combination with the line concatenation character allows you to write multi-line ''IF ... THEN'' blocks: 
- 
- if x = y then ~ 
- print "the numbers are equal" : ~ 
- print "whatever else here" : ~ 
- eq = 1 ~ 
- else ~ 
- print "the numbers are not equal" : ~ 
- eq = 0 
-  
-The above is technically a single line in **XC=BASIC**. 
- 
-Note that no other characters are allowed after the ''~'', not even a whitespace! 
  
 ====== Performance tip ====== ====== Performance tip ======
  
 An ''ON ... GOTO'' or ''ON ... GOSUB'' construct is faster than its ''IF ... THEN GOTO/GOSUB'' equivalent. Please refer to the [[ON|ON construct]] for details. An ''ON ... GOTO'' or ''ON ... GOSUB'' construct is faster than its ''IF ... THEN GOTO/GOSUB'' equivalent. Please refer to the [[ON|ON construct]] for details.