This template demonstrates what will happen when you attempt to pass parameters to a template in various ways.
This template takes 4 parameters -- a, b, c, and d. In the example below, they are used in the template call as follows:
- a -- leave out of the call
- b -- include, but without an =
- c -- include, with an = but no value
- d -- include, with an = and a value
{{About parameters|b|c=|d=value}}
| name | #if: {{{p}}} | #if: {{{p|}}} | "{{{p|subst}}}" | #ifeq: {{{p|+}}}|{{{p|-}}} |
|---|---|---|---|---|
| a | non-empty | empty | "subst" | != |
| b | non-empty | empty | "subst" | != |
| c | empty | empty | "" | = |
| d | non-empty | non-empty | "value" | = |
