Calculate Running Total from Array

[Stuart Shay]

Hello All:

I have a array which contains the totals for each month and from this array
I want to get a running total for each month

decimal[] month = new decimal[12];
month[0] = 254; (Jan)
month[1] = 78; (Feb)
month[2] = 34; (Mar)
ect ...

What is the best way I can easily obtain the Running Total for each month

decimal[] monTotal = new decimal[12];
monTotal[0] = 254; (Jan - Running Total)
monTotal[1] = 332; (Feb - Running Total)
monTotal[2] = 366; (Mar- Running Total)

Thanks
Stuart

[Michael C]

"Stuart Shay" <ss***@yahoo.comwrote in message
news:64**********************************@microsof t.com...

Hello All:

I have a array which contains the totals for each month and from this
array I want to get a running total for each month

decimal[] month = new decimal[12];
month[0] = 254; (Jan)
month[1] = 78; (Feb)
month[2] = 34; (Mar)
ect ...

What is the best way I can easily obtain the Running Total for each month

decimal[] monTotal = new decimal[12];
monTotal[0] = 254; (Jan - Running Total)
monTotal[1] = 332; (Feb - Running Total)
monTotal[2] = 366; (Mar- Running Total)

decimal total = 0;
for(int i = 0; i < month.Length; i++)
{
total += month[i];
monTotal = total;
}

This might not be the sort of thing you'd keep in an array because you now
have duplicate data and the 2 sets of data could become inconsistant, eg if
you change month[0] but don't recalculate monTotal. I wouldn't say it is
wrong to store the running totals but you should only do it if you have a
reason.

>
Thanks
Stuart

[TonyJ]

Hello!

First of all there are 12 month in a year and the index start at 0 so you
should have 11 not 12.
Second you could use the foreach statement instead of a for loop in this
way.
decimal total = 0;
foreach (Decimal dec in month)
{
total += dec;
}

//Tony

"Michael C" <mi**@nospam.comskrev i meddelandet
news:u$*************@TK2MSFTNGP05.phx.gbl...

"Stuart Shay" <ss***@yahoo.comwrote in message
news:64**********************************@microsof t.com...

Hello All:

I have a array which contains the totals for each month and from this
array I want to get a running total for each month

decimal[] month = new decimal[12];
month[0] = 254; (Jan)
month[1] = 78; (Feb)
month[2] = 34; (Mar)
ect ...

What is the best way I can easily obtain the Running Total for each

month

decimal[] monTotal = new decimal[12];
monTotal[0] = 254; (Jan - Running Total)
monTotal[1] = 332; (Feb - Running Total)
monTotal[2] = 366; (Mar- Running Total)

decimal total = 0;
for(int i = 0; i < month.Length; i++)
{
total += month[i];
monTotal = total;
}

This might not be the sort of thing you'd keep in an array because you now
have duplicate data and the 2 sets of data could become inconsistant, eg

if

you change month[0] but don't recalculate monTotal. I wouldn't say it is
wrong to store the running totals but you should only do it if you have a
reason.

Thanks
Stuart

[rossum]

On Wed, 3 Oct 2007 13:46:08 +1000, "Michael C" <mi**@nospam.com>
wrote:

>"Stuart Shay" <ss***@yahoo.comwrote in message
news:64**********************************@microso ft.com...

>Hello All:

I have a array which contains the totals for each month and from this
array I want to get a running total for each month

decimal[] month = new decimal[12];
month[0] = 254; (Jan)
month[1] = 78; (Feb)
month[2] = 34; (Mar)
ect ...

What is the best way I can easily obtain the Running Total for each month

decimal[] monTotal = new decimal[12];
monTotal[0] = 254; (Jan - Running Total)
monTotal[1] = 332; (Feb - Running Total)
monTotal[2] = 366; (Mar- Running Total)

decimal total = 0;
for(int i = 0; i < month.Length; i++)
{
total += month[i];
monTotal = total;

I suspect you meant: monTotal[i] = total;

>}

This might not be the sort of thing you'd keep in an array because you now
have duplicate data and the 2 sets of data could become inconsistant, eg if
you change month[0] but don't recalculate monTotal. I wouldn't say it is
wrong to store the running totals but you should only do it if you have a
reason.

Depending on efficiency issues it may be required to keep the running
totals in an array. An example would be where the updates were very
infrequent (once a month) but the reads much more common (many times a
day).

You are right about duplicate data, there would need to be a boolean
flag to trigger a recalculation of the running totals whenever one of
the month totals was changed. All this can be built into the relevant
class properties/indexes/methods if required.

rossum

>

>>
Thanks
Stuart

[Chris Shepherd]

TonyJ wrote:

Hello!

First of all there are 12 month in a year and the index start at 0 so you
should have 11 not 12.

This is not correct. You want an array sized to 12, not 11. If I do:

object[] o = new object[12];

it creates 12 entries. This is independent of the index.
Example:

static void Main(string[] args)
{
decimal[] decs = new decimal[12];
string msg = "";
for (int i = 0; i < decs.Length; i++)
{
decs[i] = decimal.Parse(i.ToString());
msg += "index: " + i.ToString() + "\n";
}
MessageBox.Show(msg);
}

Will pop up a messagebox with 12 items (index 0 through 11).
Chris.

[Michael C]

"TonyJ" <jo*****************@telia.comwrote in message
news:e5**************@TK2MSFTNGP04.phx.gbl...

Hello!

First of all there are 12 month in a year and the index start at 0 so you
should have 11 not 12.
Second you could use the foreach statement instead of a for loop in this
way.
decimal total = 0;
foreach (Decimal dec in month)
{
total += dec;
}

I disagree. In this case you won't have an index to store the total back
into an array.

Michael

[Michael C]

"rossum" <ro******@coldmail.comwrote in message
news:m9********************************@4ax.com...

I suspect you meant: monTotal[i] = total;

Yes.

>>This might not be the sort of thing you'd keep in an array because you now
have duplicate data and the 2 sets of data could become inconsistant, eg
if
you change month[0] but don't recalculate monTotal. I wouldn't say it is
wrong to store the running totals but you should only do it if you have a
reason.

Depending on efficiency issues it may be required to keep the running
totals in an array. An example would be where the updates were very
infrequent (once a month) but the reads much more common (many times a
day).

That's exactly what I was saying, you would need a good reason to do this.
It shouldn't be something that is done by default.

You are right about duplicate data, there would need to be a boolean
flag to trigger a recalculation of the running totals whenever one of
the month totals was changed. All this can be built into the relevant
class properties/indexes/methods if required.

>
rossum

>>

>>>
Thanks
Stuart