# Sum of elements in an array

I'm working on a simple assignment for a summer java course and was just hoping you guys could take a look at my code and see if the way I did it is the best way. The purpose is to create a simple `int` array with at least 25 elements and use a loop to traverse it and add up all the elements. I had some issues but looks like I got it to work. After I work it out I did a little research and saw some similar stuff where people were using a For Each loop (enhanced loop). Would that be a better option? I'm kinda confused on the best ways to use that opposed to a regular for loop.

Anyway, any comments or criticism in helping me be a better programmer!

``````public class Traversals {

public static void main(String[] args) {

int absenceTotal = 0;
// initialize array with 30 days of absences.
int absencesArr[] = { 1, 3, 0, 9, 8, 23, 1,
11, 23, 5, 6, 7, 10, 1, 5,
14, 2, 4, 0, 0, 1, 3, 2, 1,
1, 0, 0, 1, 3, 7, 2 };

for (int i = 0; i < absencesArr.length; i++) {
absencesArr[i] += absenceTotal;
absenceTotal = absencesArr[i];
}
System.out.println("There were " + absenceTotal + " absences that day.");
}
}
``````

## 评论

### Don't modify the array. I wo

Don't modify the array. I would prefer the for-each loop. And you should consider that there may be a very large number of students, so I would probably use a `long` for `sum`. And formatted output. Putting that together into something like

``````long sum = 0;
for(int i : absencesArr) {
sum += i;
}
// System.out.println("There were " + sum + " absences that day.");
System.out.printf("There were %d absences that day.%n", sum);
``````

### public class Traversals {

``````public class Traversals {

public static void main(String[] args) {

int absenceTotal = 0;
// initialize array with 30 days of absences.
int absencesArr[] = { 1, 3, 0, 9, 8, 23, 1,
11, 23, 5, 6, 7, 10, 1, 5,
14, 2, 4, 0, 0, 1, 3, 2, 1,
1, 0, 0, 1, 3, 7, 2 };

for (int i = 0; i < absencesArr.length; i++) {
// remove this
//absencesArr[i] += absenceTotal;
}
System.out.println("There were " + absenceTotal + " absences that day.");
}
}
``````

### In Java 8 you can use stream

In Java 8 you can use stream api:

``````public class Traversals {
public static void main(String[] args) {

int absenceTotal = 0;
// initialize array with 30 days of absences.

int absencesArr[] = { 1, 3, 0, 9, 8, 23, 1,
11, 23, 5, 6, 7, 10, 1, 5,
14, 2, 4, 0, 0, 1, 3, 2, 1,
1, 0, 0, 1, 3, 7, 2 };

absenceTotal = IntStream.of(array).sum();

System.out.println("There were " + absenceTotal + " absences that day.");
}
}
``````

### shortest way i know would be

shortest way i know would be :

``````int sum=Arrays.stream(absencesArr).sum();
``````

### In addition to other nice co

In addition to other nice contributions, I am fan of `for-each loop` and will typically do it in one line.

``````for(int i : absencesArr) absenceTotal += i;
System.out.printf("There were %d absences that day.", absenceTotal);
``````

But in some situations when I want to have control over my Object size/length/count, I will use `for loop` like following example:

``````for (int i = 0; i < absencesArr.length; i++) absenceTotal += absencesArr[i];
System.out.printf("There were %d absences that day.", absenceTotal);
``````

And if I need to have more then one line of codes inside the `for loop` or `for-each loop` then I will put them all inside curly brackets `{ more than one line of code }`.