JavaScript で漢数字からアラビア数字に変換

kansuji2arabic.js

// https://qiita.com/dosec/items/c6aef40fae6977fd89ab
// から移植＋α
// とりあえず
// （文字列）.kansuji2arabic(split3)
// で動作

(function(){
	// 改良版 typeOf（のさらに改良）
	// http://qiita.com/Hiraku/items/87e5d1cdaaa475c80cc2
	var typeOf = function(x) {
		if (x === null) return 'null';
		if (x == null) return 'undefined';
		var type = typeof x, c = x.constructor, cName = c && c.name ? c.name : '';
		if (type === 'object') {
			if(jQuery && x instanceof jQuery){
				return 'jQuery';
			}
			return cName ? cName :
				Object.prototype.toString.call(x).slice(8, -1);
		}
		if(cName && type == cName.toLowerCase()){
			return cName;
		}
		return type;
	};
	// 汎用 compare 関数
	compareStringLenAsc = function(a, b){
		return a.length - b.length;
	};
	compareStringLenDesc = function(a, b){
		return b.length - a.length;
	};
	// プロトタイプのメソッド拡張
	var extendMethod = function(object, methodName, method, forceOverwrite) {
		if(typeof object[methodName] === 'undefined' || forceOverwrite){
			if(typeof Object.defineProperty !== 'function') {
				object[methodName] = method;
			} else {
				Object.defineProperty(object, methodName, {
					configurable: false,
					enumerable: false,
					value: method,
				});
			}
		}
	};

	// String プロトタイプ拡張
	// 全置換
	// （文字列）.replaceAll(（置換対象）,（置換語）)
	extendMethod(String.prototype, 'replaceAll', function(org, dest){
		var orgRE = new RegExp(org, 'g');
		return this.replace(orgRE, dest);
	});
	// 全角の数値を半角に
	// （文字列）.numZenToHan()
	var _zenExcepts = [
			{from:'．', to:'.'},
			{from:'－', to:'-'},
			{from:'ー', to:'-'}
		];
	extendMethod(String.prototype, 'numZenToHan', function(){
		var result = this;
		for(var i = 0; i < 10; i++){
			result = result.replaceAll(String.fromCharCode(65296+i),String.fromCharCode(48+i));
		}
		_zenExcepts.forEach(function(value, index){
			result = result.replaceAll(value.from, value.to);
		});
		return result;
	});
	// 漢数字の置換テーブル
	var kansujiTransTable = {'零':'〇','壱':'一','壹':'一','弌':'一','弐':'二','貳':'二','参':'三','參':'三','肆':'四','伍':'五','陸':'六','漆':'七','柒':'七','質':'七','捌':'八','玖':'九','廿':'二十','卅':'三十','丗':'三十','卌':'四十','佰':'百','陌':'百','仟':'千','阡':'千','萬':'万'},
		kansujiList = kansujiREList = '〇一二三四五六七八九',
		kansujiUnits = {'十':10,'百':100,'千':1000},
		kansujiUnitsRE = new RegExp('[十百千]|[^十百千]+','g'),
		kansujiMansRE = new RegExp('[万億兆]|[^万億兆]+','g'),
		kansujiMans = {'万':10000,'億':100000000,'兆':1000000000000};
	Object.keys(kansujiUnits).forEach(function(value, index){
		kansujiREList += value;
	});
	Object.keys(kansujiMans).forEach(function(value, index){
		kansujiREList += value;
	});
	var kansujiRE = new RegExp('(['+kansujiREList+'\\d]+)','g');
	// 漢数字からアラビア数字に変換
	// （文字列）.kansuji2arabic(split3)
	extendMethod(String.prototype, 'kansuji2arabic', function(split3){
		var kansujistr = this.numZenToHan();
		var protoMap = Array.prototype.map;
		var transValue = function(num, re, dic){
			var tmpre = re || kansujiUnitsRE,
				tmpdic = dic || kansujiUnits,
				unit = 1,
				result = 0,
				match = num.match(tmpre).reverse();

			match.forEach(function(value, index){
				if(tmpdic[value]){
					if(unit > 1) {
						result += unit;
					}
					unit = tmpdic[value];
				} else {
					var val = (!isNaN(value)) ? parseInt(value) : transValue(value);
					result += val * unit;
					unit = 1;
				}
			});
			if(unit > 1) {
				result += unit;
			}
			return result;
		};
		Object.keys(kansujiTransTable).forEach(function(value, index){
			kansujistr = kansujistr.replaceAll(value, kansujiTransTable[value]);
		});
		if(kansujistr && kansujiRE.test(kansujistr)){
			var match = kansujistr.match(kansujiRE).unique().sort(compareStringLenDesc);
			match.forEach(function(value, index){
				var tempValue = '' + value;
				protoMap.call(kansujiList, function(x, ind){
					tempValue = tempValue.replaceAll(x, ind);
				});
				tempValue = transValue(tempValue, kansujiMansRE, kansujiMans);
				if(split3){
					tempValue = tempValue.splitComma(3);
				} else {
					tempValue = '' + tempValue;
				}
				kansujistr = kansujistr.replaceAll(value, tempValue);
			});
		}
		return kansujistr;
	});
	// Number プロトタイプ拡張
	// 数値をカンマ区切り
	// （数値）.splitComma(digit)
	// 文字列で返るので注意
	extendMethod(Number.prototype, 'splitComma', function(digit){
		var tmpDigit = digit || 3,
			digitRE = new RegExp('^([+-]?\\d+)(\\d{'+tmpDigit+'})'),
			to = String(this),
			tmp = '';
		while(to != (tmp = to.replace(digitRE,function(){return arguments[1]+','+arguments[2]}))){
			to = tmp;
		}
		return to;
	});
	// Array プロトタイプ拡張
	// 配列の重複を取り除く
	// （Array）.unique(numStrSame)
	extendMethod(Array.prototype, 'unique', function(numStrSame){
		var targetArray = this,
			storageDict = {},
			resultArray = [];
		targetArray.forEach(function(value){
			var key = numStrSame ? String(value) : typeOf(value)+':'+value;
			if(!storageDict.hasOwnProperty(key)){
				storageDict[key] = true;
				resultArray.push(value);
			}
		});
		return resultArray;
	});
})();