working around a null element in an array

Question

In my program, i "deleted" an element by turning it into a null as you can't delete an element from an array so employee [i] = null. However, I was wondering, if I wanted to work with the array that had a null element, like add all the numbers in the array, how do I do this without any problems?

[UPDATE:]

My array contains the first names, last names and ages of 4 employees, I've "deleted" one of the employees details by making it null. As per all of the suggestions I got, I tried to add all the ages using:

int sum = 0;

for (int i = 0; i < employee.length; i++) {
    if (employee[i] != null)
        sum += employee[i].getAge();
}

but all I get is that sum = 1.

spinlok · Accepted Answer · 2014-03-29 22:14:34Z

1

If the only operation you're going to perform on your array is the sum of all elements, it would make more sense to set the deleted elements to 0 instead of null. This way, you will not need the extra null check on every iteration.

answered Mar 29, 2014 at 22:14

spinlok

3,68123 silver badges28 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

user3452963 Over a year ago

my array does not contain only number, it contains the first names, last names and ages of 4 employees. I want to add the ages of 3 employees after I've deleted one of the employees information.

spinlok Over a year ago

Ok, in that case you will need the null check like other answers have pointed out. Also, a cleaner way to do this is to put your Employee objects in a List, so you can use the .remove() method to delete elements in the list.

user3452963 Over a year ago

I tried that. But that just keep giving me that the sum of employee[i].getAge is 1.

spinlok Over a year ago

Have you tried printing out all the (non-null) elements of the array? What does this show you?

user3452963 Over a year ago

That works fine. All the elements are printed out (except for the null one).

Christian Tapia · Accepted Answer · 2014-03-29 22:04:48Z

0

You have to check if that element is null or not. If it is, add to the sum. If not, do nothing.

int sum = 0;

for (int i = 0; i < employee.length; i++) {
    if (employee[i] != null)
        sum += employee[i];
}

answered Mar 29, 2014 at 22:04

Christian Tapia

34.2k7 gold badges58 silver badges73 bronze badges

1 Comment

user3452963 Over a year ago

I did

int sum = 0;  for (int i = 0; i < employee.length; i++) {     if (employee[i] != null)         sum += employee[i].getAge; }

and the sum keeps coming up to 1 all the time.

demongolem · Accepted Answer · 2014-03-29 22:19:45Z

0

public int addAllNums(int[] nums) { int sum=0; for(int i=0;i<nums.length;i++) { if(nums[i]!=null)sum+=nums[i]; } }

edited Mar 29, 2014 at 22:19

demongolem

9,76436 gold badges97 silver badges107 bronze badges

answered Mar 29, 2014 at 22:01

faeophyta

3235 silver badges16 bronze badges

2 Comments

faeophyta Over a year ago

@demongolem, thanks for the edit. Didn't see that. :)

faeophyta Over a year ago

Two of the other answers are exactly what I posted. How to remove duplicate answers?

Fidan Hakaj · Accepted Answer · 2014-08-07 12:04:17Z

0

You just have to iterate over your array and check if the current employee is not null :

int sum = 0;
for(int i = 0; i < employee.length; i++) {
    if(employee[i] != null) {
        sum += employe[i].getNumber();
    }
}

edited Aug 7, 2014 at 12:04

answered Mar 29, 2014 at 22:04

Fidan Hakaj

7,1733 gold badges33 silver badges33 bronze badges

Collectives™ on Stack Overflow

working around a null element in an array

4 Answers 4

5 Comments

1 Comment

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

5 Comments

1 Comment

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related