将双精度数转换为不带小数位的字符串的最佳方法

Question

What is the best way to convert a double to String without decimal places?

What about String.valueOf((int) documentNumber)?

The doubles always have 0 after the decimal dot. I don't need to round or truncate

Answer 1

If you are sure that the double is indeed an integer use this one:

NumberFormat nf = DecimalFormat.getInstance();
nf.setMaximumFractionDigits(0);
String str = nf.format(documentNumber);

As a bonus, this way you keep your locale's configuration as in thousand separator.

EDIT
I add this previously removed option as it seems that was useful to the OP:

Double.valueOf(documentNumber).intValue();

Answer 2

你可以试试这个：

String numWihoutDecimal = String.valueOf(documentNumber).split("\\.")[0];

Answer 3

You can convert a double to string with the minimum necessary precision:

public static String ceonvert(double d)
{
    if(d == (long) d)
        return String.format("%d",(long)d);
    else
        return String.format("%s",d);
}

Or this :

> new DecimalFormat("#.##").format(2.199); //"2.2"

Answer 4

我不确定这是否是最好的方式，但我确信这是最短的方式：

((int)documentNumber) + ""

Answer 5

鉴于新编辑的问题指出双打实际上是整数，我想说您建议的答案String.valueOf((int) documentNumber)很棒。

Answer 6

The easiest way to convert a double to string is to use quotation marks and then the double after that. double d = 123; String a = "" + d;

Another way is to use the toString method if you want to keep the way you converted it hidden

public String toString()
{
   String a + ""  d;
} 

Answer 7

I had a similar issue where Gson converted what should have been an Integer value to a Double and I wanted to write it as a String. NumberFormat works, but you also need to disable the grouping delimiter otherwise it outputs 1,234,567:

Object num = new Double(1234567);
NumberFormat nf = DecimalFormat.getIntegerInstance();
nf.setGroupingUsed(false);
String str = nf.format((Number)num);

Answer 8

Quotation Marks + Double

String s = "" + 0.07;

LOL this is the best way, (obviously for experienced programmers)!