使用DecimalFormat显示填充零 [英] Show padding zeros using DecimalFormat
问题描述
$ b
DecimalFormat dec = new DecimalFormat(#)使用DecimalFormat将双精度格式化为2位小数。 ##)。
double rawPercent =((double)(count.getCount()。intValue())/
(double)(total.intValue()))* 100.00;
double percentage = Double.valueOf(dec.format(rawPercent));
它可以工作,但如果我有一个像20的数字,它会给我这个:
20.0
我想这样:
20.00
任何建议吗?
DecimalFormat类用于将十进制数值转换为字符串。在你的例子中,你正在从格式()方法来的字符串,并把它放回到一个双变量。如果你正在输出这个双变量,你将看不到格式化的字符串。请参阅下面的代码示例及其输出:
int count = 10;
int total = 20;
DecimalFormat dec = new DecimalFormat(#。00);
double rawPercent =((double)(count)/(double)(total))* 100.00;
double percentage = Double.valueOf(dec.format(rawPercent));
System.out.println(DF Version:+ dec.format(rawPercent));
System.out.println(double version:+ percentage);
输出:
DF Version:50.00
double version:50.0
I'm using DecimalFormat to format doubles to 2 decimal places like this:
DecimalFormat dec = new DecimalFormat("#.##");
double rawPercent = ( (double)(count.getCount().intValue()) /
(double)(total.intValue()) ) * 100.00;
double percentage = Double.valueOf(dec.format(rawPercent));
It works, but if i have a number like 20, it gives me this:
20.0
and I want this:
20.00
Any suggestions?
The DecimalFormat class is for transforming a decimal numeric value into a String. In your example, you are taking the String that comes from the format( ) method and putting it back into a double variable. If you are then outputting that double variable you would not see the formatted string. See the code example below and its output:
int count = 10;
int total = 20;
DecimalFormat dec = new DecimalFormat("#.00");
double rawPercent = ( (double)(count) / (double)(total) ) * 100.00;
double percentage = Double.valueOf(dec.format(rawPercent));
System.out.println("DF Version: " + dec.format(rawPercent));
System.out.println("double version: " + percentage);
Which outputs:
"DF Version: 50.00"
"double version: 50.0"
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