Dart\u306e\u6570\u5024\u578b\u306fnum\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u3067\u8868\u73fe\u3055\u308c\u307e\u3059\u3002\u3053\u306e\u30a4\u30f3\u30bf\u30d5\u30a7\u30fc\u30b9\u3092\u7d99\u627f\u3059\u308b\u578b\u3068\u3057\u3066\u3001int\u3068double\u304c\u3042\u308a\u307e\u3059\u3002
\n
\nint\u306f\u4efb\u610f\u306e\u30b5\u30a4\u30ba\u3067\u8868\u73fe\u3055\u308c\u3001double\u306fIEEE 754 standard \u3067\u5b9a\u7fa9\u3055\u308c\u3066\u3044\u308b64bit\u3067\u8868\u73fe\u3055\u308c\u3066\u3044\u307e\u3059\u3002int\u3060\u3051\u304c\u6d6e\u52d5\u5c0f\u6570\u70b9\u3092\u3082\u3061\u307e\u305b\u3093\u3002\u3053\u306e\u578b\u306f\u3001List\u306e\u6dfb\u5b57\u3067\u5229\u7528\u3067\u304d\u307e\u3059\u3002\u4ed6\u306e\u578b\u306f\u6d6e\u52d5\u5c0f\u6570\u70b9\u3092\u6301\u3061\u307e\u3059\u3002<\/p>\n
num\u306e\u521d\u671f\u5024\u306f\u30010\u3067\u306f\u306a\u304f\u3001null\u306b\u306a\u308a\u307e\u3059\u3002\u6b21\u306e\u4f8b\u3067\u306f\u300c(a == null).toString()\u300d\u306ftrue\u3068\u306a\u308a\u307e\u3059\u3002\u7d76\u5bfe\u5024\u3092\u6c42\u3081\u308babs()\u3084\u3001\u5207\u308a\u4e0a\u3052\u308bceil()\u3001\u5207\u308a\u6368\u3066\u308bfloor()\u3082\u3042\u308a\u307e\u3059\u3002\u4ed6\u306e\u51e6\u7406\u3092\u3057\u305f\u3044\u5834\u5408\u306f\u3001Math\u30af\u30e9\u30b9\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u78ba\u8a8d\u3057\u3066\u307f\u308c\u3070\u826f\u3044\u3067\u3057\u3087\u3046\u3002<\/p>\n
\r\nvoid main() {\r\n num a;\r\n print((a == null).toString()); \/\/ true\r\n\r\n double x = 1.41421356;\r\n print("x.abs() : ${x.abs()}");\r\n print("x.ceil() : ${x.ceil()}");\r\n print("x.floor() : ${x.floor()}");\r\n \r\n num y = 1.234;\r\n num e0 = 1.23e4;\r\n print("y:${y}, e0:${e0}");\r\n\r\n \/\/ \u6570\u5b57\u3092int\u578b\u3078\u5909\u63db\r\n int n = Math.parseInt("1");\r\n \/\/ \u6570\u5b57\u3092double\u578b\u3078\u5909\u63db\r\n double d = Math.parseDouble("3.14159");\r\n \/\/ int\u578b\u3092\u6570\u5b57\u3078\u5909\u63db\r\n String ns = 1.toString();\r\n \/\/ double\u578b\u3092\u6570\u5b57\u3078\u5909\u63db\r\n String ds = x.toStringAsFixed(2);\r\n print("n:${n}, d:${d}, ns:${ns}, ds:${ds}");\r\n}\r\n<\/pre>\n\u300ce0 = 1.23e4\u300d\u306f\u3001\u300c1.23\u307810\u306e4\u4e57\u3092\u304b\u3051\u305f\u5024\u3092e0\u3078\u4ee3\u5165\u3059\u308b\u300d\u3068\u3044\u3046\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002\u6570\u5b57\u3092int\u578b\u3084double\u578b\u3078\u5909\u63db\u3059\u308b\u30e1\u30bd\u30c3\u30c9\u306fMath\u30af\u30e9\u30b9\u306b\u3042\u308a\u307e\u3059\u3002int\u578b\u3084double\u578b\u3092\u6570\u5b57\u306b\u5909\u63db\u3059\u308b\u306b\u306f\u3001toString()\u3084toStringAsFixed()\u304c\u3042\u308a\u307e\u3059\u3002\u306a\u304a\u3001Web\u30a2\u30d7\u30ea\u3067\u3001\u5165\u529b\u5024\u3092\u6570\u5024\u3078\u5909\u63db\u3057\u305f\u3044\u5834\u5408\u306f\u3001HTMLInputElement.valueAsNumber() \u3092\u4f7f\u3046\u3068\u3044\u3046\u624b\u3082\u3042\u308a\u307e\u3059\u3002<\/p>\n
\u5b9f\u884c\u7d50\u679c\u306f\u6b21\u306e\u901a\u308a<\/p>\n
\r\ntrue\r\nx.abs() : 1.41421356\r\nx.ceil() : 2.0\r\nx.floor() : 1.0\r\ny:1.234, e0:12300.0\r\nn:1, d:3.14159, ns:1, ds:1.41\r\n<\/pre>\n