1. double运算
c = parseFloat(a) + parseFloat(b))
2. 四舍五入,保留两位小数
c = c.toFixed(2);
3. 去掉小数点后面多余的0
c = c.toFixed(2)*100/100;
JAVA中
//四舍五入,保留指定小数位 public static Double roundDouble(Object obj, int scale){ double d = 0; try{ d = Double.parseDouble(obj.toString().replaceAll(",", "")); } catch (Exception e) { d = 0; } //四舍五入,保留两位小数 BigDecimal bd = new BigDecimal(d); bd = bd.setScale(scale, BigDecimal.ROUND_HALF_UP); d = bd.doubleValue(); return d; } //转成字符串,去掉科学计数法 public static String roundFormat(Object obj){ String str = "0"; try{ Double d = Double.parseDouble(obj.toString().replaceAll(",", "")); //四舍五入,保留两位小数 BigDecimal bd = new BigDecimal(d); bd = bd.setScale(2, BigDecimal.ROUND_HALF_UP); d = bd.doubleValue(); //去除科学计数法 DecimalFormat df = new DecimalFormat("#.##"); str = df.format(d); } catch (Exception e) { str = "0"; } return str; } //除法 public static Double divideRound(Double a, Double b){ try { if (b == 0) { return 0.0; } else { BigDecimal bd = new BigDecimal(a/b); bd = bd.setScale(2, BigDecimal.ROUND_HALF_UP); double d = bd.doubleValue(); bd = null; return d; } } catch (Exception e) { return 0.0; } }