Template:Ifdef/doc

Documentation

{{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}.

Usage

{{Ifdef/doc|value|result}} yields result  if value  isn't blank.

This template is used to simplify the following equivalent but somewhat cryptic code variants:

{{{1{{{1|}}}|{{{2}}}}}}

{{{value{{{value|}}}|{{{result}}}}}}

{{{test{{{test|}}}|{{{then}}}}}}

Example

Code	Result
1 {{Ifdef/doc| |empty}}	1 ==Documentation== {{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}. Usage {{Ifdef/doc|value|result}} yields result  if value  isn't blank. This template is used to simplify the following equivalent but somewhat cryptic code variants: {{{1{{{1|}}}|{{{2}}}}}} {{{value{{{value|}}}|{{{result}}}}}} {{{test{{{test|}}}|{{{then}}}}}} Example Code Result 1 {{Ifdef/doc| |empty}} 1 2 {{Ifdef/doc|x|gotcha}} 2 3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}} 3 4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}} 4 5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}} 5 6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }} 6 7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }} 7 8 {{Ifdef/doc| oops | see=[[#Caveats]] }} 8 See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code. Caveats In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required: For | template:! (edit•talk•links•history) offers a workaround. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}". Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}. See also {{Ifdef}} {{Ifndef}} {{Qif}} Parser functions #expr:, #if:, #ifeq:, etc. Source Copied from the page on meta where it is released under the GFDL.
2 {{Ifdef/doc|x|gotcha}}	2 ==Documentation== {{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}. Usage {{Ifdef/doc|value|result}} yields result  if value  isn't blank. This template is used to simplify the following equivalent but somewhat cryptic code variants: {{{1{{{1|}}}|{{{2}}}}}} {{{value{{{value|}}}|{{{result}}}}}} {{{test{{{test|}}}|{{{then}}}}}} Example Code Result 1 {{Ifdef/doc| |empty}} 1 2 {{Ifdef/doc|x|gotcha}} 2 3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}} 3 4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}} 4 5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}} 5 6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }} 6 7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }} 7 8 {{Ifdef/doc| oops | see=[[#Caveats]] }} 8 See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code. Caveats In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required: For | template:! (edit•talk•links•history) offers a workaround. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}". Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}. See also {{Ifdef}} {{Ifndef}} {{Qif}} Parser functions #expr:, #if:, #ifeq:, etc. Source Copied from the page on meta where it is released under the GFDL.
3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}}	3 ==Documentation== {{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}. Usage {{Ifdef/doc|value|result}} yields result  if value  isn't blank. This template is used to simplify the following equivalent but somewhat cryptic code variants: {{{1{{{1|}}}|{{{2}}}}}} {{{value{{{value|}}}|{{{result}}}}}} {{{test{{{test|}}}|{{{then}}}}}} Example Code Result 1 {{Ifdef/doc| |empty}} 1 2 {{Ifdef/doc|x|gotcha}} 2 3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}} 3 4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}} 4 5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}} 5 6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }} 6 7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }} 7 8 {{Ifdef/doc| oops | see=[[#Caveats]] }} 8 See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code. Caveats In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required: For | template:! (edit•talk•links•history) offers a workaround. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}". Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}. See also {{Ifdef}} {{Ifndef}} {{Qif}} Parser functions #expr:, #if:, #ifeq:, etc. Source Copied from the page on meta where it is released under the GFDL.
4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}}	4 ==Documentation== {{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}. Usage {{Ifdef/doc|value|result}} yields result  if value  isn't blank. This template is used to simplify the following equivalent but somewhat cryptic code variants: {{{1{{{1|}}}|{{{2}}}}}} {{{value{{{value|}}}|{{{result}}}}}} {{{test{{{test|}}}|{{{then}}}}}} Example Code Result 1 {{Ifdef/doc| |empty}} 1 2 {{Ifdef/doc|x|gotcha}} 2 3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}} 3 4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}} 4 5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}} 5 6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }} 6 7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }} 7 8 {{Ifdef/doc| oops | see=[[#Caveats]] }} 8 See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code. Caveats In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required: For | template:! (edit•talk•links•history) offers a workaround. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}". Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}. See also {{Ifdef}} {{Ifndef}} {{Qif}} Parser functions #expr:, #if:, #ifeq:, etc. Source Copied from the page on meta where it is released under the GFDL.
5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}}	5 ==Documentation== {{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}. Usage {{Ifdef/doc|value|result}} yields result  if value  isn't blank. This template is used to simplify the following equivalent but somewhat cryptic code variants: {{{1{{{1|}}}|{{{2}}}}}} {{{value{{{value|}}}|{{{result}}}}}} {{{test{{{test|}}}|{{{then}}}}}} Example Code Result 1 {{Ifdef/doc| |empty}} 1 2 {{Ifdef/doc|x|gotcha}} 2 3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}} 3 4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}} 4 5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}} 5 6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }} 6 7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }} 7 8 {{Ifdef/doc| oops | see=[[#Caveats]] }} 8 See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code. Caveats In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required: For | template:! (edit•talk•links•history) offers a workaround. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}". Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}. See also {{Ifdef}} {{Ifndef}} {{Qif}} Parser functions #expr:, #if:, #ifeq:, etc. Source Copied from the page on meta where it is released under the GFDL.
6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }}	6 ==Documentation== {{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}. Usage {{Ifdef/doc|value|result}} yields result  if value  isn't blank. This template is used to simplify the following equivalent but somewhat cryptic code variants: {{{1{{{1|}}}|{{{2}}}}}} {{{value{{{value|}}}|{{{result}}}}}} {{{test{{{test|}}}|{{{then}}}}}} Example Code Result 1 {{Ifdef/doc| |empty}} 1 2 {{Ifdef/doc|x|gotcha}} 2 3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}} 3 4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}} 4 5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}} 5 6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }} 6 7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }} 7 8 {{Ifdef/doc| oops | see=[[#Caveats]] }} 8 See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code. Caveats In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required: For | template:! (edit•talk•links•history) offers a workaround. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}". Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}. See also {{Ifdef}} {{Ifndef}} {{Qif}} Parser functions #expr:, #if:, #ifeq:, etc. Source Copied from the page on meta where it is released under the GFDL.
7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }}	7 ==Documentation== {{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}. Usage {{Ifdef/doc|value|result}} yields result  if value  isn't blank. This template is used to simplify the following equivalent but somewhat cryptic code variants: {{{1{{{1|}}}|{{{2}}}}}} {{{value{{{value|}}}|{{{result}}}}}} {{{test{{{test|}}}|{{{then}}}}}} Example Code Result 1 {{Ifdef/doc| |empty}} 1 2 {{Ifdef/doc|x|gotcha}} 2 3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}} 3 4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}} 4 5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}} 5 6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }} 6 7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }} 7 8 {{Ifdef/doc| oops | see=[[#Caveats]] }} 8 See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code. Caveats In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required: For | template:! (edit•talk•links•history) offers a workaround. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}". Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}. See also {{Ifdef}} {{Ifndef}} {{Qif}} Parser functions #expr:, #if:, #ifeq:, etc. Source Copied from the page on meta where it is released under the GFDL.
8 {{Ifdef/doc| oops | see=[[#Caveats]] }}	8 ==Documentation== {{ifdef/doc}} is a compact variant of {{Qif}} for simple "if defined then do" statements without else part. It's the opposite of {{ifndef}}. Usage {{Ifdef/doc|value|result}} yields result  if value  isn't blank. This template is used to simplify the following equivalent but somewhat cryptic code variants: {{{1{{{1|}}}|{{{2}}}}}} {{{value{{{value|}}}|{{{result}}}}}} {{{test{{{test|}}}|{{{then}}}}}} Example Code Result 1 {{Ifdef/doc| |empty}} 1 2 {{Ifdef/doc|x|gotcha}} 2 3 {{Ifdef/doc| {{{1| }}} | {{{1| }}} undefined}} 3 4 {{Ifdef/doc| {{{1|x}}} | {{{1|x}}} for an u}} 4 5 {{Ifdef/doc| {{{ 1 }}} | {{{1}}} bad idea}} 5 6 {{Ifdef/doc| {{!}} |see also {{Tlx|Qif}} }} 6 7 {{Ifdef/doc| okay | 2=see=[[#Caveats]] }} 7 8 {{Ifdef/doc| oops | see=[[#Caveats]] }} 8 See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code. Caveats In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required: For | template:! (edit•talk•links•history) offers a workaround. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}". Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}. See also {{Ifdef}} {{Ifndef}} {{Qif}} Parser functions #expr:, #if:, #ifeq:, etc. Source Copied from the page on meta where it is released under the GFDL.

See also a simpler example using ifdef. There's no default in ifdef for the second parameter, because this could hide problematic code.

Caveats

In templates the characters "=" (=) and "|" (|) cannot be used as is in parameters. The numeric character references = and | are often good enough, but for Wiki and XHTML markup the literal characters are required:

1. For | template:! (edit•talk•links•history) offers a workaround.
2. For = the template parameter mechanism allows {{ifdef}} resulting in "ok=yes" instead of {{ifdef}} resulting in "{{{2}}}".

Substitution works only for {{ifdef}}, but not for {{ifndef}} or {{qif}}.

See also

• {{Ifdef}}
• {{Ifndef}}
• {{Qif}}
• Parser functions #expr:, #if:, #ifeq:, etc.

Source

Copied from the page on meta where it is released under the GFDL.