Double轉換大數字出現精度丟失或者錯誤，如18位或以上的數字超過100000000000000000打印出來就會出現錯誤，用BigDecimal或者BigInteger能解決問題，Double的最大值也遠遠超過這個了呀，想知道為啥Double類型為什么會這種情況？    NumberFormat nf = NumberFormat.getInstance();    nf.setGroupingUsed(false);     System.out.println(nf.format(Double.valueOf("100000000000000000")));//100000000000000000     System.out.println(nf.format(Double.valueOf("100000000000000001")));//100000000000000000     System.out.println(nf.format(Double.parseDouble("100000000000000216")));//100000000000000224     System.out.println(new BigDecimal("100000000000000216"));//100000000000000216