https://forge.codesys.com/forge/talk/Engineering/thread/65be32a57d/2022-04-10T19:13:55.411000ZRecent posts to Codesys ST instructions2022-04-10T19:13:55.411000Z2022-04-10T19:13:55.411000Zludecushttps://forge.codesys.com/u/ludecus/https://forge.codesys.com5ad071f840576d48eeb04fe1befd6b04aeafcc89

<div class="markdown_content"><p>In CODESYS the IF is a statement. So the semicolon after the END_IF is needless. Only for assignment or calls is a semicolon required.</p></div>

2022-04-09T06:58:03.978000Z2022-04-09T06:58:03.978000Zdamian177https://forge.codesys.com/u/damian177/https://forge.codesys.com29f9afcd05a3cdae95b32ded5acc7f04e6906afb

<div class="markdown_content"><p>the semicolon after END_IF has any meaning?</p></div>

2022-04-08T13:33:12.934000Z2022-04-08T13:33:12.934000Zludecushttps://forge.codesys.com/u/ludecus/https://forge.codesys.com6ab998e59550caf9f128c8f061a6e1f758bd203e

<div class="markdown_content"><p>To be honest, i love to pass a boolean as the return value for methods. Therefore i could simple call the method as a condition in IF statements.</p> <div class="codehilite"><pre><span></span><span class="err">IF iDevice &lt;&gt; 0 AND_THEN iDevice.mReadValues()</span> <span class="err">THEN</span> <span class="err"> &lt;instrcutions&gt;;</span> <span class="err">END_IF</span> </pre></div> </div>

2022-04-08T13:03:18.919000Z2022-04-08T13:03:18.919000Zh-hermsenhttps://forge.codesys.com/u/hermsen/https://forge.codesys.com0ea286b4d393b4cd35e8be10a80f3af925e50695

<div class="markdown_content"><p>IF branching should be avoided by replacing it with a CASE statement if that is a possibility.</p></div>

2022-04-08T13:03:14.411000Z2022-04-08T13:03:14.411000Zh-hermsenhttps://forge.codesys.com/u/hermsen/https://forge.codesys.com40cfee4cc5e02d0476318df8bd747275331b0677

<div class="markdown_content"><p>IF branching should be avoided by replacing it with a CASE statement if that is a possibility.</p></div>

2022-04-08T12:58:59.157000Z2022-04-08T12:58:59.157000Zh-hermsenhttps://forge.codesys.com/u/hermsen/https://forge.codesys.com5f2320f84aa28506f16b5ca92426546e0ceff0fe

<div class="markdown_content"><p>This is only useful when the method returns some boolean.<br/> To be honest I am personally not a huge fan of the AND_THEN extension as I dont need the AND_THEN that much. </p></div>

2022-04-08T10:59:36.422000Z2022-04-08T10:59:36.422000Zludecushttps://forge.codesys.com/u/ludecus/https://forge.codesys.comad04665419fd3943440a209a5ff5966c3b86bcaf

<div class="markdown_content"><p>Just as hint: For reference/pointer/interface checks you could also use AND_THEN</p> <div class="codehilite"><pre><span></span><span class="err">IF itfInterface&lt;&gt;0 AND_THEN itfInterface.Method THEN &lt;instructions&gt;; END_IF</span> <span class="err">IF pointer&lt;&gt;0 AND_THEN pointer.value THEN &lt;instructions&gt;; END_IF</span> </pre></div> </div>

2022-04-07T15:25:04.403000Z2022-04-07T15:25:04.403000Ztvmhttps://forge.codesys.com/u/tvm/https://forge.codesys.com01dd273091e65ba7784b051a02bd990165bf7f97

<div class="markdown_content"><p>No real difference when there's only one elsif statement, but consider what your code would look like if there was more than one</p> <p>this:</p> <div class="codehilite"><pre><span></span><span class="k">IF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="n">ELSIF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="n">ELSIF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="n">ELSIF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"> </span> <span class="k">ELSE</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="p">;</span><span class="w"></span> </pre></div> <p>is easier to understand and troubleshoot than this:</p> <div class="codehilite"><pre><span></span><span class="k">IF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="k">ELSE</span><span class="w"> </span> <span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="w"> </span><span class="k">ELSE</span><span class="w"></span> <span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="w"> </span><span class="k">ELSE</span><span class="w"></span> <span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="w"> </span><span class="k">ELSE</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="w"> </span><span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="w"></span> <span class="w"> </span><span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="w"></span> <span class="w"> </span><span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="w"></span> <span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="w"></span> </pre></div> </div>

2022-04-07T11:48:35.677000Z2022-04-07T11:48:35.677000Zsgronchihttps://forge.codesys.com/u/sgronchi/https://forge.codesys.comb70543134c380e178312fbc07dfde92ffaf88cbe

<div class="markdown_content"><p>Yes. You'll suffer for multiple END_IFs in the second case.</p></div>

2022-04-07T09:31:33.669000Z2022-04-07T09:31:33.669000Zdamian177https://forge.codesys.com/u/damian177/https://forge.codesys.com75620158f8870b7b91c0f165bc1732fcef6d2ec6

<div class="markdown_content"><p>Please explain to me what is the difference between the following instructions :?<br/> Can I use both interchangeably?</p> <div class="codehilite"><pre><span></span><span class="k">IF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="n">ELSIF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="k">ELSE</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="p">;</span><span class="w"></span> </pre></div> <div class="codehilite"><pre><span></span><span class="k">IF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="k">ELSE</span><span class="w"> </span><span class="k">IF</span><span class="w"> </span><span class="o">[</span><span class="n">conditional_expresion</span><span class="o">]</span><span class="w"> </span><span class="k">THEN</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="k">ELSE</span><span class="w"></span> <span class="w"> </span><span class="o">&lt;</span><span class="n">instructions</span><span class="o">&gt;</span><span class="p">;</span><span class="w"></span> <span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="w"></span> <span class="k">END</span><span class="w"> </span><span class="k">IF</span><span class="w"></span> </pre></div> </div>