Code to Parse dollars and cents?

Question

I've written code to parse dollars and cents entered by the user. The value returned is the total number of cents.

For example:

f('1ドル.50') = 150
f('1.5') = 150
f('0') = 0
f('1000') = 1000
f('12,500ドル.00') = 12500000
functions.GetTotalCents = function (dollarsAndCentsString) {
 // Cast the value passed in to a string in case a number was passed in.
 dollarsAndCentsString = dollarsAndCentsString.toString();
 // First, discard the '$' glyph, if it was passed in.
 if (dollarsAndCentsString.split('$').length == 2)
 dollarsAndCentsString = dollarsAndCentsString.split('$')[1];
 // If the user delimmited the groups of digits with commas, remove them.
 dollarsAndCentsString = dollarsAndCentsString.replace(/,/g, '');
 // Next, divide the resulting string in to dollars and cents.
 var hasDecimal = (dollarsAndCentsString.split('.')).length == 2;
 var dollarsString, centsString;
 dollarsString = dollarsAndCentsString.split('.')[0];
 var centsString = hasDecimal ? dollarsAndCentsString.split('.')[1] : '0';
 var dollars = parseInt(dollarsString, 10);
 var cents;
 if (centsString.length == 1)
 cents = parseInt(centsString, 10) * 10;
 else cents = parseInt(centsString, 10);
 if (cents > 99 || isNaN(cents) || isNaN(dollars) || !isFinite(dollars) || !isFinite(cents))
 return 0;
 var totalCents = dollars * 100 + cents;
 return totalCents;
};

Anyone care to critique my code?

Answer 1

Wouldn't it be simpler to:

• strip out any '$' and ',' characters;
• convert to a real number;
• multiply by 100;
• take the integer part.

You can probably do that in one line (my Javascript is a bit rusty):

return Math.round(100 * parseFloat(dollarsAndCentsString.replace(/[,ドル]/g, '')));

Having said that, I think your f('1000') example is probably wrong: my intuition says I should interpret '1000' as dollars, not cents.

• Vivian River: I'll consider your ideas. For what it's worth, the reason that I consider the dollars and cents separately as real numbers is to avoid floating point arithmetic round-off errors. Perhaps they are not relevant in this context. 0.1 + 0.2 = 0.30000000000000004.
• Vivian River: And you're right f('1000') should be 10000.