编辑“︁Template:Inflation/doc”︁（章节）

==== 提示與技巧 ====
===== 貨幣轉換 =====

此模板不能轉換貨幣單位，因此，如果想知道1960時的1000德國馬克於現在的價值，輸入{{tlx|Inflation|DE|1000|1960|r{{=}}2}}顯示的數值仍爲德國馬克，而非歐元。

所以，如要轉換貨幣單位，需要手動輸入數式，下面例子定義€ 1 = DM 1.95583：

* {{aye}} <tt><nowiki>{{#expr:</nowiki>({{tlx|Inflation|DE|1000|1960|r{{=}}2}}<nowiki> / 1.95583) round 2}}</nowiki></tt>

===== 四捨五入 =====

{{para|r}}參數可以定義要四捨五入的數位，輸入{{para|r|2}}會約至2個小數點；輸入{{para|r|-3}}會約至千位；輸入{{para|r|-6}}會約至百萬位，如此類推。

===== Formatnum =====

為達到更佳效果，編者可以使用<tt><nowiki>{{</nowiki>[[Help:魔術字|formatnum:]]<nowiki>}}</nowiki></tt>，用{{tlx|Formatprice}}也可。這個功能為數值每三個數位加上一個分隔逗號，但編者不能控制顯示多少小數位。

* {{aye}} <tt>'''DM''' <nowiki>{{formatnum:</nowiki>{{tlx|Inflation|DE|1000000|1957|1978}}<nowiki>}}</nowiki>'''.00'''</tt> = DM {{formatnum:{{Inflation|DE|1000000|1957|1978}}}}.00
* {{aye}} <tt>'''£'''<nowiki>{{formatnum:</nowiki>{{tlx|Inflation|UK|1000000|1323|1978|r{{=}}-4}}<nowiki>}}</nowiki></tt> = £{{formatnum:{{Inflation|UK|1000000|1323|1978|r=-4}}}}
* {{aye}} <tt>'''$'''<nowiki>{{formatnum:</nowiki>{{tlx|Inflation|US|1000000|1990|r{{=}}2}}<nowiki>}}</nowiki></tt> = ${{formatnum:{{Inflation|US|1000000|1990|r=2}}}}

{{TransH}}
Another potential source of difficulties resides in the way certain calculated values are expressed. In many cases the result comes as a number in engineering units ("1.2E+9" instead of "1200000000"), and when that happens <tt><nowiki>{{</nowiki>[[Help:Magic words#Formatting|formatnum:]]<nowiki>}}</nowiki>'ing</tt> the result fails. A workaround then is to express the value to be inflated with fewer digits, adding a multiplier text such as "million" after the result, and then hitting the "Show preview" button as many times as needed, changing parameters until the best result is found:

* {{nay}} <tt>'''$'''<nowiki>{{formatnum:</nowiki>{{tlx|Inflation|US|1000000000|1900|r{{=}}-8}}<nowiki>}}</nowiki></tt> = ${{formatnum:{{Inflation|US|1000000000|1900|r=-8}}}}
* {{nay}} <tt>'''$'''<nowiki>{{formatnum:</nowiki>{{tlx|Inflation|US|1000000|1900|r{{=}}-5}}<nowiki>}}</nowiki> ''thousand''</tt> = ${{formatnum:{{Inflation|US|1000000|1900|r=-5}}}} thousand
* {{aye}} <tt>'''$'''<nowiki>{{formatnum:</nowiki>{{tlx|Inflation|US|1000|1900|r{{=}}-2}}<nowiki>}}</nowiki> ''million''</tt> = ${{formatnum:{{Inflation|US|1000|1900|r=-2}}}} million
* {{aye}} <tt>'''$'''<nowiki>{{formatnum:</nowiki>{{tlx|Inflation|US|1|1900|r{{=}}1}}<nowiki>}}</nowiki> ''billion''</tt> = ${{formatnum:{{Inflation|US|1|1900|r=1}}}} billion

The following section provides an automated way of avoiding this trial and error scenario.

===== Formatprice =====

{{tlx|Formatprice}} is a template specifically designed to display price values, both big and small, in a more pleasant way than <tt><nowiki>{{</nowiki>[[Help:Magic words#Formatting|formatnum:]]<nowiki>}}</nowiki></tt> allows for. For example, instead of showing the whole of a huge number such as "953,783,409,856.12", it would show it as "{{Formatprice|953783409856.12}}", while small numbers have their cents part appearing as expected, "1234.5" being properly shown as "{{Formatprice|1234.5}}".

On the down side, {{tlx|Formatprice}} has no built-in intelligent handling of user locale settings, which means that some users might see a dot or a comma the opposite way they'd expect. As a general rule of thumb this shouldn't be a serious concern though, as most numbers in Wikipedia are hand-written anyway and will show as entered regardless of user settings.

* {{aye}} <tt>'''DM''' <nowiki>{{</nowiki>[[Template:Formatprice|Formatprice]]<nowiki>|</nowiki>{{tlx|Inflation|DE|1000000|1957|1978}}<nowiki>}}</nowiki></tt> = DM {{Formatprice|{{Inflation|DE|1000000|1957|1978}}}}
* {{aye}} <tt>'''£'''<nowiki>{{</nowiki>[[Template:Formatprice|Formatprice]]<nowiki>|</nowiki>{{tlx|Inflation|UK|1000000|1323|1978|r{{=}}-4}}<nowiki>}}</nowiki></tt> = £{{Formatprice|{{Inflation|UK|1000000|1323|1978|r=-4}}}}
* {{aye}} <tt>'''$'''<nowiki>{{</nowiki>[[Template:Formatprice|Formatprice]]<nowiki>|</nowiki>{{tlx|Inflation|US|1000000|1990|r{{=}}2}}<nowiki>}}</nowiki></tt> = ${{Formatprice|{{Inflation|US|1000000|1990|r=2}}}}
* {{aye}} <tt>'''$'''<nowiki>{{</nowiki>[[Template:Formatprice|Formatprice]]<nowiki>|</nowiki>{{tlx|Inflation|US|1000000000|1900|r{{=}}-8}}<nowiki>}}</nowiki></tt> = ${{Formatprice|{{Inflation|US|1000000000|1900|r=-8}}}}

===== Documenting =====

It's a good practice to provide a valid reference for the prices calculated with this template in the articles where it's used. The template {{tl|Inflation/fn|country}} was developed to ease this task. It accepts as its single parameter the same country codes used here, and will generate one or more appropriate footnotes. Typically, this is how a piece of text using it looks like:

* <tt><nowiki>In 1910 a ''blah'' cost on average £1,000. This is equivalent to £{{Formatprice|{{Inflation|</nowiki>'''UK'''<nowiki>|1000|1910|r=2}}}} in present day </nowiki>{{Nowrap|terms.<nowiki>{{Inflation/fn|</nowiki>'''UK'''<nowiki>}}</nowiki>}}</tt>

Resulting in this converted code (notice the footnote link at the end):

* In 1910 a ''blah'' cost on average £1,000. This is equivalent to £{{Formatprice|{{Inflation|UK|1000|1910|r=2}}}} in present day terms.{{Inflation/fn|UK}}

The footnote thus generated appears whenever {{tlx|reflist}} or <tt><nowiki><references /></nowiki></tt> is used in an article, usually in its "References" section. See below for the live example in this document's own [[Template:Inflation#References|References]] section, or click the above generated footnote to jump to it.