Delete element from Array directly

Question

I have an array like below:

PersonClass[] person= {
            new PersonClass("90234234434", "John", "Smith", 22, "Street 22/5", 10//this is priority from 0 up to 10),
            ...
            ...
    };

Then I search for a security ID that starts from 98

for(int n = 0; n < person.length; n++)
    {
        if(person[n].getSecId().contains("98"))
        {
            System.out.println(person[n].toString());s
            //delete this object from person array
        }
    }

Now my question is: Can I delete this object directly from the array, if not how can I convert it into collection eg. ArrayList.

duplicate https://stackoverflow.com/questions/642897/removing-an-element-from-an-array-java — Ruslan, Feb 10 '19 at 11:30
Possible duplicate of [How do I remove objects from an array in Java?](https://stackoverflow.com/questions/112503/how-do-i-remove-objects-from-an-array-in-java) — Tristan, Feb 10 '19 at 11:30
by the way.. if you want to check if ID starts with 98 you should use `startsWith()` method — Ruslan, Feb 10 '19 at 11:33
A remark: If you want to delete `Person`s which `secId`s start with, some string, use [`String#startsWith(...)`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html#startsWith(java.lang.String)) instead of [`String#contains(...)`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/String.html#contains(java.lang.CharSequence)). — Turing85, Feb 10 '19 at 11:38
Every other post on stackoverflow didn't solve my problem. I want to delete it straight from array, not from collections. — G. Dawid, Feb 10 '19 at 11:40

YCF_L · Accepted Answer · 2019-02-11T19:37:04.120

2

If you are using Java 8 you can use :

person = Arrays.stream(person)
           .filter(p -> !p.getSecId().startsWith("98")) // note the not ! here
           .toArray(PersonClass[]::new);

Another thing :

Then I search for security ID that starts from 98

in this case you can replace contains with startsWith to just check the first characters.

edited Feb 11 '19 at 19:37

answered Feb 10 '19 at 11:34

YCF_L

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I'm using Java 8 and that solve my problem thanks. Could you please, explain a little bit how it exactly work? – G. Dawid Feb 10 '19 at 11:45
1

@G.Dawid the idea is simple you just need to filter the secId which not start with "98" then collect the result as an array and assign the result to your first array – YCF_L Feb 10 '19 at 11:48
2

@G.Dawid You want to use `filter`. The `dropWhile` operation does something completely different. – Stuart Marks Feb 11 '19 at 04:53
@G.Dawid, StuartMarks is correct, after I read my answer I realize that the second way is not correct in your case – YCF_L Feb 11 '19 at 19:38
@StuartMarks you are correct, I totally forgot the `dropWhile` utilities – YCF_L Feb 11 '19 at 19:39

score 0 · Answer 2 · answered Feb 10 '19 at 14:24

0

You could use the static method java.util.Arrays.asList() to covert an array into an ArrayList

answered Feb 10 '19 at 14:24

willi b.

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This is poorly documented, but the List returned by Arrays.asList() does not support structural (add or remove) operations. It and its iterator only support replacing existing elements. – Matt Leidholm Feb 11 '19 at 14:24

Delete element from Array directly

2 Answers2