macro/command/ifthenelseif.html

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  <title>if, then, elseif, else, endif</title>
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<h1>if, then, elseif, else, endif</h1>

<p>
Conditional branching
</p>

<h2>1) Format 1</h2>

<pre class="macro-syntax">
if &lt;expression&gt; &lt;statement&gt;
</pre>

<h3>Remarks</h3>

<p>
Executes a &lt;statement&gt;, if &lt;expression&gt; is true(non-zero).
</p>

<h3>Example</h3>

<pre class="macro-example">
; If A&gt;1, jump to ':label'.
if A&gt;1 goto label

; If result&lt;&gt;0, assign 0 to A.
if result A=0
</pre>


<h2>2) Format 2</h2>

<pre class="macro-syntax">
if &lt;expression 1&gt; then
  ...
  (Statements for the case:  &lt;expression 1&gt; is true (non-zero).)
  ...
[elseif &lt;expression 2&gt; then]
  ...
  (Statements for the case:  &lt;expression 1&gt; is false (zero) and &lt;expression 2&gt; is true.)
  ...
[elseif &lt;expression N&gt; then]
  ...
  (Statements for the case:  &lt;expression 1&gt;, &lt;expression 2&gt;,... and &lt;expression N-1&gt; are all false, and &lt;expression N&gt; is true.)
  ...
[else]
  ...
  (Statements for the case:  all the conditions above are false (zero).)
  ...
endif
</pre>

<h3>Remarks</h3>

<p>
'if' and 'elseif' statements must end with 'then'.<br>
'elseif' and 'else' can be omitted.<br>
'endif' can not be omitted.
</p>

<h3>Example</h3>

<pre class="macro-example">
if a=1 then
  b = 1
  c = 2
  d = 3
endif

if i&lt;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
</pre>


<h3>*) NOTICE</h3>

<em>(version 4.90 or later)</em><br>
By using Format 2(if - endif), the syntax error occurs when then is not described.

<pre class="macro-example">
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
</pre>


<h2>See also</h2>
<ul>
  <li><a href="../syntax/expressions.html">Expressions and operators</a></li>
</ul>

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