kanji-levels.js

See code in use and check kanji levels of text with Kanji Level Check.

• parse text for Japanese kanji
• see the jōyō grade, JLPT level, and WaniKani level of each kanji
• determine readability of Japanese text based on grade/level of kanji
• count number of times a kanji is used, find most frequently used kanji
• filter kanji by category (jōyō, jinmeiyō, hyōgai) or level

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Kanji Object

Kanji() returns a kanji object when given a single-character String that (according to its UTF-8 code) is Japanese kanji. Otherwise returns undefined.

Examples:

// returns object when given single kanji character
Kanji("会");
// -> Object {...}

// returns undefined when given more than one character
Kanji("文字");
// -> undefined

// returns undefined if character is not kanji
Kanji("の");
// -> undefined

The returned object has the following attributes:

attribute	values	description
character	single-character String	the kanji character that defines the object
category	"jōyō", "jinmeiyō", "hyōgai"	describes if kanji character is part of the list of common kanji taught in school ("jōyō"), used in names and is not jōyō ("jinmeiyō"), or is neither and more obscure ("hyōgai")
joyo	1, 2, 3, 4, 5, 6, 9, undefined	indicates the school year in which the kanji are taught in Japan (grade 9 includes all jōyō kanji not in the kyōiku list of grades 1-6)
jlpt	"N5", "N4", "N3", "N2", "N1", undefined	indicates lowest level JLPT examination in which the kanji should be known
wk	1..60, undefined	indicates at which level the kanji is taught by WaniKani

The object will return its character when the toString() method is called.

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KanjiCollection Object

KanjiCollection() returns a kanjicollection object when given a String of text that contains kanji. Otherwise returns undefined.

Examples:

// returns object when given String containing kanji
KanjiCollection("自分を信じて。");
// -> Object {...}

// returns undefined when given String without kanji
KanjiCollection("おはよう！");
// -> undefined

KanjiCollection.all is a kanjicollection object containing all 2998 jōyō and jinmeiyō kanji.

The returned object has the following attributes:

attribute	value	description
collection	Array	an array of kanji objects ordered by appearance in text, kanji can repeat

The object has the following methods:

method	parameters	returns	description
unique	-	Array	an array of unique kanji objects ordered by appearance in text
count	single-kanji String	Number	count the number of times a kanji appears in collection
countTotal	-	Number	returns this.collection.length
countUnique	-	Number	returns this.unique().length
mostFrequent	Number	Object	sorts this.collection by frequency of kanji, returns object with count and characters of kanji ranked by frequency
highestWk	-	1..60	returns WaniKani level of kanji with highest
highestJoyo	-	1, 2, 3, 4, 5, 6, 9	returns Jōyō grade of kanji with highest
highestJlpt	-	"N5", "N4", "N3", "N2", "N1"	returns JLPT level of kanji with highest
percentReadable	{digits, wk, joyo, jlpt}	'Number%'	takes given WaniKani/Jōyō/JLPT level(s) and returns percent of kanji in collection that can be read at that level, to decimal precision of digits (defaults to 0 digits after decimal)
filterMax	{wk, joyo, jlpt}	Object	returns a kanjicollection object that is filtered to contain only kanji with levels below or equal to given arguments
filterMin	{wk, joyo, jlpt}	Object	returns a kanjicollection object that is filtered to contain only kanji with levels above or equal given arguments
filterEqual	{wk, joyo, jlpt}	Object	returns a kanjicollection object that is filtered to contain only kanji with levels equal to given arguments
filterCategory	category String	Object	returns a kanjicollection object that is filtered to contain only kanji of given category