# Using an Accumulator

When using an accumulating variable there are three stages:

Initialise
We declare our accumulator and set it to an initial values.
Update
Inside the loop we update the accumulator - we take into account the current data item.
Output/use
After the loop our accumulator contains the required value. We use it or output it.

## Using an accumulator to add.

Print the total of all of the numbers

• We initialise to 0.
• We add to the accumulator.
• The value printed is the sum 0+2+7+1+1.

[Font] [Default] [Show] [Resize] [History] [Profile]

## Using an accumulator to count.

Print the number of items in the list.

• We initialise to 0.
• We increment the accumulator.
• The value printed is the count: 0+1+1+1+1.

[Font] [Default] [Show] [Resize] [History] [Profile]

## Using an accumulator to count on a condition.

Count the number of 1s in the list

• We initialise to 0.
• We increment the accumulator only if the current value equals 1.

[Font] [Default] [Show] [Resize] [History] [Profile]

## Using an accumulator to multiply.

• We initialise to 1.
• We multiply the accumulator.
• The value printed is the product: 1*2*7*1*1

[Font] [Default] [Show] [Resize] [History] [Profile]

## Using an accumulator to find the maximum.

• We initialise to 0.
• We take the max.
• The value printed is the largest:
`max(max(max(max(0,2),7),1),1)`

[Font] [Default] [Show] [Resize] [History] [Profile]

## Using an accumulator to concatenate.

• We initialise to "".
• We concatenate the next value.
• Each time i gets converted to a string and is put at the end.

[Font] [Default] [Show] [Resize] [History] [Profile]

## Using two accumulators to find the mean.

• We initialise both to 0.
• We add to the sum and increment the count.
• We divide the sum by the count to get the average.

[Font] [Default] [Show] [Resize] [History] [Profile]

## Using an accumulator to calculate.

• We initialise to 0.