模板:Yesno/doc

{{Yesno}} (or {{YesNo}}) evaluates any input and produces a normalized yes or nil output, based on the content of the input and several configurable options. It is not used in article prose, but in coding complex templates.

Usage

The template distinguishes five different types of input, supplied on the first unnamed parameter:

1. Yes: Case-insensitive forms of Yes, y, true, on, and 1; e.g. {{Yesno|<yEs>}} → yes
2. No: Case-insensitive forms of No, n, false, off, and 0; e.g. {{Yesno|<nO>}} →
3. Nothing: When the input is defined but either contains no value or consists of whitespace character only; i.e. {{Yesno|}} or {{Yesno|< >}} →
4. Negation: When the input is either ¬ (alt code 170) or entirely missing; i.e. {{Yesno|<¬>}} or {{Yesno}} →
5. Anything else: e.g. {{Yesno|<Purple monkey dish washer>}} → yes

By default, the template returns "yes" in the first and last case but returns nil (blank, empty string) in the other cases.

Two short-hand templates for the most common uses that override the default behavior:

• {{yesno-yes}} or {{YesNo-Yes}} – always returns "yes" (or the specified replacement result in |yes=) unless an explicit negative value is given; i.e., it evaluates to "yes" even when the value is empty or missing.
• {{yesno-no}} or {{YesNo-No}} – always returns "no" (or the specified replacement result in |no=) unless an explicit positive value is given; i.e., it evaluates to "no" even when the value is present, as long as it does not contain anything that resolves to "yes".

Customizing the output

Template's default output can be customized with five named parameters, respectively: |yes=, |no=, |blank=, |¬= and |def=. If these parameters are specified, the template response is as follows:

1. Yes: Template returns the contents of |yes=, otherwise returns "yes". For example:
   • {{yesno|<y>|<yes=Yeah>}} results in "Yeah"
   • {{yesno|<y>|<yes=bacon>}} results in "bacon"
2. No: Template returns the contents of |no=, otherwise returns blank. For example:
   • {{yesno|<n>|<no=Nay>}} results in "Nay"
   • {{yesno|<n>|<no=ham>}} results in "ham"
3. Nothing: Template returns the contents of |blank=, or of |no= in absence of the former; otherwise, returns blank.
   • {{yesno|<>|<blank=eggs>}} results in "eggs"
   • {{yesno|<>|<no=ham>}} results in "ham"
   • {{yesno|<>|<blank=eggs>|<no=ham>}} results in "eggs"
4. Negation: Template returns the contents of |¬=, otherwise returns blank. For example:
   • {{yesno|<¬>|<¬=sausage>}} results in "sausage"
5. Anything else: Template returns the contents of |def=, or of |yes= in absence of the former; otherwise, returns "yes".
   • {{yesno|<purple monkey dish washer>|<def=cup of tea>}} results in "cup of tea"
   • {{yesno|<purple monkey dish washer>|<yes=bacon>}} results in "bacon"
   • {{yesno|<purple monkey dish washer>|<def=cup of tea>|<yes=bacon>}} results in "cup of tea"

For the named parameters, use of a blank value is not the same as omitting the parameter. A blank named parameter tells the template that the customized return value is blank. For example:

• {{yesno|<purple monkey dish washer>}} results in "yes"
• {{yesno|<purple monkey dish washer>|<def=>}} results in "" [blank]

Logical distinctions

Overview of {{yesno}} logical values and their associated texts
Input parameter 1 (1=)	In code	Logical return value	Default return text		Return text when set: yes=Pos no=Neg blank=Blank ¬=Undefined def=Def	Note
yes, y, true, 1*	{{yesno|yes}}	yes by definition	"yes"		"Pos"	* Case-insensitive (Y=y)
Some Text	{{yesno|Some Text}}	yes by default	"yes"		"Def"	"Pos" when def=[omitted]
no, n, false, 0*	{{yesno|no}}	no by definition	"" [blank]		"Neg"	* Case-insensitive (N=n)
[blank]	{{yesno|}}	blank	"" [blank]		"Blank"	"Neg" when blank=[omitted]
1=[blank]	{{yesno|1=}}	blank	"" [blank]		"Blank"	"Neg" when blank=[omitted]
¬	{{yesno|¬}}	¬	"" [blank]		"Undefined"
[omitted]	{{yesno}}	¬	"" [blank]		"Undefined"

Comparison with related templates
Input parameter 1 (1=)	{{yesno}}	{{yesno-yes}}	{{yesno-no}}
yes, y, true, 1*	"yes"	"yes"	"yes"
Some Text	"yes"	"yes"	"no"
no, n, false, 0*	"" [blank]	"no"	"no"
[blank]	"" [blank]	"yes"	"no"
1=[blank]	"" [blank]	"yes"	"no"
¬	"" [blank]	"yes"	"no"
[omitted]	"" [blank]	"yes"	"no"

Full parameter list

Unnamed parameter 1= the input value to be evaluated. The other parameters (all named, all optional), are the return values for their respective logical outcome. When set, each one overrules their default return value.

{{yesno
| Input value
| yes = Output on yes
| no = Output on no
| blank = Output on blank input
| ¬ = Output on ¬
| def = Definite output
}}

See also

• U+00AC ¬ NOT SIGN (¬)
• Module:yesno
• {{Yesno-yes}} – variant of Yesno that defaults to "yes" if value is not explicitly negative
  • {{Yesno-yes/fallback}} – variant that first defaults to the yes parameter, then falls back to "yes", if value is not explicitly negative
• {{Yesno-no}} – variant of Yesno that defaults to "no" if value is not explicitly positive

TemplateData

This is the TemplateData for this template used by TemplateWizard, VisualEditor and other tools. See a monthly parameter usage report for Template:Yesno in articles based on its TemplateData.

TemplateData for Yesno

This template normalises an input to be a yes or nil output.

模板参数

参数		描述	类型	状态
Input value	1	The value to be evaluated	字符串	必需
Output on yes	yes	Specifies the output of the template when the input value is a case-insensitive forms of 'Yes', 'Y', 'True' or '1'	字符串	可选
Output on no	no	Specifies the output of the template when the input value is a case-insensitive forms of 'No', 'N', 'False, or '0'	字符串	可选
Output on blank input	blank	Specifies the output of the template when the input value is defined but is either empty or contains nothing but whitespace character(s)	字符串	可选
Output on ¬	¬	Specifies the output of the template when the input value is either '¬' or entirely missing (undefined)	字符串	可选
Definite output	def	Specifies the output of the template when the input value is defined but not a form of 'yes', 'no', '1', '0', '¬' or blank	字符串	可选