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A Gentle Introduction to
Java Programming

Tutorial: Accumulating values.

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.

1. Using an accumulator to add.

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

test text

2. Using an accumulator to count.

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

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3. Using an accumulator to multiply.

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

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4. 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)
```

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5. 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.
The answer is ""+2+7+1+1

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6. 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.

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7. Using an accumulator to calculate.

We initialise to 0.
We multiply by the radix and add the next digit.
By the end the number 2 has been multiplied by 10 three times, the number has been multiplied by 10 twice...
10*(10*(10*2+7)+1)+1

test text