JAVA筆記:double四捨五入並保留兩位小數的方法

1.只要輸出結果

double x1 = 0.026;
System.out.println(String.format("%.2f", x1));

2.數據轉換

//方案一:
get_double = (double)(Math.round(result_value*100)/100.0)
//方案二:
DecimalFormat df = new DecimalFormat("#.##"); 
get_double = Double.ParseDouble(df.format(result_value));
//方案三:
get_double = Double.ParseDouble(String.format("%.2f",result_value));
//方案四:
BigDecimal bd = new BigDecimalresult_value();
BigDecimal  bd2 = bd.setScale(2,BigDecimal  .ROUND_HALF_UP);
get_double = Double.ParseDouble(bd2.ToString());

3.只保留兩位小數(不含四捨五入)

double d = 13.4324;
d=((int)(d*100))/100;