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<p>erroneous construct:</p>

<p><syntaxhighlight lang="dosbatch">IF ==bar ECHO Equal</syntaxhighlight></p>

<p>Similarly, if <code>%foo%</code> contains <code>abc def</code>, then a different syntax error results:</p>

<p><syntaxhighlight lang="dosbatch">IF abc def==bar ECHO Equal</syntaxhighlight></p>

<p>The usual way to prevent this problem is to surround variable expansions in quotes so that an empty variable expands into the valid expression <code>IF ""=="bar"</code> instead of the invalid <code>IF ==bar</code>. The text that is being compared</p><p>
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