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FAQ Topic - How do I convert a Number into a String with
exactly 2 decimal places?
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When formatting money for example, to format 6.57634 to
6.58, 6.5 to 6.50, and 6 to 6.00?
Rounding of x.xx5 is uncertain, as such numbers are not
represented exactly. See section 4.7 for Rounding issues.
N = Math.round(N*10 0)/100 only converts N to a Number of value
close to a multiple of 0.01; but document.write( N) does not give
trailing zeroes.
ECMAScript Ed. 3.0 (JScript 5.5 [but buggy] and JavaScript 1.5)
introduced N.toFixed, the main problem with this is the bugs in
JScripts implementation.
Most implementations fail with certain numbers, for example 0.07.
The following works successfully for M>0, N>0:
--
Postings such as this are automatically sent once a day. Their
goal is to answer repeated questions, and to offer the content to
the community for continuous evaluation/improvement. The complete
comp.lang.javas cript FAQ is at http://jibbering.com/faq/index.html.
The FAQ workers are a group of volunteers. The sendings of these
daily posts are proficiently hosted by http://www.pair.com.
FAQ Topic - How do I convert a Number into a String with
exactly 2 decimal places?
-----------------------------------------------------------------------
When formatting money for example, to format 6.57634 to
6.58, 6.5 to 6.50, and 6 to 6.00?
Rounding of x.xx5 is uncertain, as such numbers are not
represented exactly. See section 4.7 for Rounding issues.
N = Math.round(N*10 0)/100 only converts N to a Number of value
close to a multiple of 0.01; but document.write( N) does not give
trailing zeroes.
ECMAScript Ed. 3.0 (JScript 5.5 [but buggy] and JavaScript 1.5)
introduced N.toFixed, the main problem with this is the bugs in
JScripts implementation.
Most implementations fail with certain numbers, for example 0.07.
The following works successfully for M>0, N>0:
Code:
function Stretch(Q, L, c) { var S = Q
if (c.length>0) while (S.length<L) { S = c+S }
return S
}
function StrU(X, M, N) { // X>=0.0
var T, S=new String(Math.round(X*Number("1e"+N)))
if (S.search && S.search(/\D/)!=-1) { return ''+X }
with (new String(Stretch(S, M+N, '0')))
return substring(0, T=(length-N)) + '.' + substring(T)
}
function Sign(X) { return X>0 ? "+" : X<0 ? "-" : " " }
function StrS(X, M, N) { return Sign(X)+StrU(Math.abs(X), M, N) }
Number.prototype.toFixed = function(n){ return StrS(this,1,n) };
--
Postings such as this are automatically sent once a day. Their
goal is to answer repeated questions, and to offer the content to
the community for continuous evaluation/improvement. The complete
comp.lang.javas cript FAQ is at http://jibbering.com/faq/index.html.
The FAQ workers are a group of volunteers. The sendings of these
daily posts are proficiently hosted by http://www.pair.com.
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