How can i decrease the precision of a variable?

Question

I want to generate number between 30 to 80 and for that i use:

this.length=(float)(Math.random()*50+30);

Then i have to parse a few parameters of instance to string:

result=this.name+" by "+this.smith+" in "+this.productionYear+" at "+this.length+" length";

It generates string looking like this:

Lao Che by Youta in 1327 at 75.341866 length

How could i truncate length to have less decimal precision? I would like to set it to 2 digits after dot.

possible duplicate of [Generating random numbers in a range with Java](http://stackoverflow.com/questions/363681/generating-random-numbers-in-a-range-with-java) — stoooops, Oct 28 '13 at 18:35

Christian Tapia · Accepted Answer · 2013-10-28T18:40:20.320

2

You could do this:

import java.text.DecimalFormat;

double d = 1.234567;
DecimalFormat df = new DecimalFormat("#.##");
System.out.print(df.format(d));

Or try:

double d = 1111.234567;
String str_d = String.format("%1$.2f", d); // String.format(...) generates a new String
System.out.println("Result: " + str_d); // Now you can use it like anyother String

edited Oct 28 '13 at 18:40

answered Oct 28 '13 at 18:34

Christian Tapia

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You could also use `String.format` or just `System.out.printf`. – Darkhogg Oct 28 '13 at 18:35
But i don't want to print it. I want to add it to string with format unchanged. – Jan Jurec Oct 28 '13 at 18:40
See edit. But you want to modify the number? Or just get a string with the desired format? – Christian Tapia Oct 28 '13 at 18:42
I wanted to get string with desire format, as i said. Your solution helped me. Thank you very much. Wish you luck. – Jan Jurec Oct 28 '13 at 18:49

How can i decrease the precision of a variable?

1 Answers1