編輯模板:Infobox/doc（章節）

==== Making data fields optional ====
A row with a label but no data is not displayed. This allows for the easy creation of optional infobox content rows. To make a row optional use a parameter that defaults to an empty string, like so:

<pre style="overflow:auto">
 |  label5 = Population
 |   data5 = {{{population|}}}
</pre>{{clear}}

This way if an article doesn't define the population parameter in its infobox the row won't be displayed.

For more complex fields with pre-formatted contents that would still be present even if the parameter wasn't set, you can wrap it all in an "#if" statement to make the whole thing vanish when the parameter is not used. For instance, the "#if" statement in the following example reads "#if:the parameter ''mass'' has been supplied |then display it, followed by 'kg'":

<pre style="overflow:auto">
 |  label6 = Mass
 |   data6 = {{ #if: {{{mass|}}} | {{{mass}}} kg }}
</pre>{{clear}}

For more on #if, see [[meta:ParserFunctions##if:|here]].