if, then, elseif, else, endif

Conditional branching

1) Format 1

if <expression> <statement>

Remarks

Executes a <statement>, if <expression> is true(non-zero).

Example

; If A>1, jump to ':label'.
if A>1 goto label

; If result<>0, assign 0 to A.
if result A=0

2) Format 2

if <expression 1> then
  ...
  (Statements for the case:  <expression 1> is true (non-zero).)
  ...
[elseif <expression 2> then]
  ...
  (Statements for the case:  <expression 1> is false (zero) and <expression 2> is true.)
  ...
[elseif <expression N> then]
  ...
  (Statements for the case:  <expression 1>, <expression 2>,... and <expression N-1> are all false, and <expression N> is true.)
  ...
[else]
  ...
  (Statements for the case:  all the conditions above are false (zero).)
  ...
endif

Remarks

'if' and 'elseif' statements must end with 'then'.
'elseif' and 'else' can be omitted.
'endif' can not be omitted.

Example

if a=1 then
  b = 1
  c = 2
  d = 3
endif

if i<0 then
  i=0
else
  i=i+1
endif

if i=1 then
  c = '1'
elseif i=2 then
  c = '2'
elseif i=3 then
  c = '3'
else
  c = '?'
endif

*) NOTICE

(version 4.90 or later)
By using Format 2(if - endif), the syntax error occurs when then is not described. 
code = 100
if code != 100
	messagebox 'The code value is not 100.' 'error'
	goto error
else
	messagebox 'The code value is 100.' 'OK'
endif

:error
end

See also