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(lack of) precision

I have a form form1 where user enters two values input1 and input2.
Then a function addValues () is called:
function addValues()
{
var var1 = parseFloat(document.form1.input1.value)
var var2 = parseFloat(document.form1.input2.value)
document.form1.output.value = var1 + var2
}

When I enter 4.0001 and 1.0001 the result in my script is not 5.0002 but
5.0001999999999995
Of course this is sufficiently precise in most uses, or can be rounded off.
Still I have seen no other language where rounding errors are so prominent
after one simple addition.
Are these errors a result of parseFloat() ? Am I missing something crucial ?
Is there an easy way to increase the precision ?

TIA
Pjotr
Jul 23 '05 #1
1 1175
On Sun, 7 Nov 2004 12:50:00 +0100, Pjotr Wedersteers wrote:
When I enter 4.0001 and 1.0001 the result in my script is not 5.0002 but
5.0001999999999995
<http://www.jibbering.com/faq/#FAQ4_7>
Of course this is sufficiently precise in most uses, or can be rounded off.
Still I have seen no other language where rounding errors are so prominent
after one simple addition.
Like what languages?

Here's the result for Java..
value1: 4.0001
value2: 1.0001
value1 + 2: 5.0001999999999995
Are these errors a result of parseFloat() ? Am I missing something crucial ?


See the link above.

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Jul 23 '05 #2

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