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How to iterate between 0.1f and 1.0f with 0.1f increments in Java?
Part of my program needs to use values inside a while loop as:
0.1
0.2
0.3
...
0.9
so I need to provide them inside that loop. Here is the code:
double x = 0.0;
while ( x<=1 )
{
// increment x by 0.1 for each iteration
x += 0.1;
}
I need the output to be EXACTLY:
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
But it actually gives me something like:
0.1
0.2
0.300000000000000000000000004
0.4
0.5
0.6
0.79999999999999999999999999
0.89999999999999999999999999
0.99999999999999999999999999
780
Can I increment by 2 in a for loop in Java? If you want to increment or decrement a variable by an amount other than 1 , you can use += and -= . For example, i += 2 increments i by 2 : int i = 2; while (i <= 8) { System.
The postfix increment operator ++ adds one to a variable. Usually the variable is an integer type (byte, short, int, or long) but it can be a floating point type (float or double). No character is allowed between the two plus signs.
We need to use i+=2 in case we need to increment for loop by 2 in java. Let's say we want print all even numbers between 1 to 20 in Java. We can write a for loop and start the loop from 2 by using i=2 in initialization part and increment the loop by 2 in each iteration by using i+=2 .
the best things in life are simple. x = 12; // or some arbitruary value for( int i = 0; i < 10; i++, x++ ) { // Code... }
Welcome to the world of floating point, where 0.1 isn't 0.1. The problem is that many numbers, including 0.1, cannot be represented exactly in a double. So you aren't really adding exactly 0.1 to x each time through the loop.
One approach is to use integer arithmetic and divide by 10:
int i = 0;
while (i <= 10) {
double x = i / 10.0;
. . .
i++;
}
Another approach is to make x a BigDecimal, where you can specify that you want a particular precision. It basically is doing what the above loop does (an integer plus a scale), but packaged up in a nice class with lots of bells and whistles. Oh, and it has arbitrary precision.
137
you need to use the decimal formatter to get the expected output.
Below is the code for generating the expected output:
import java.text.DecimalFormat;
public class FloatIncrement {
public static void main (String args[]){
double x= 0.0;
DecimalFormat form = new DecimalFormat("#.#");
while(x<0.9){
x= x+0.1;
System.out.println("X : "+Double.valueOf(form.format(x)));
}
}
}
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