How do you empty an array?

[john von]

How do you empty an array?
How about multiple array?

[Rachel Swailes]

You can empty an array by running through it with a for loop and by assigning each place in the array to null or whatever your definitaion of empty is.

If it is an array of arrays then you need to run two for loops, one to loop through the outer array and one to loop through the inner arrays.

Try some code with these for loops and I'll help you out

Cheers,
Rachel

[karl koch]

why not just create a new one ?
if emptying an array is setting the elements to zero or null, then creating an new one might be faster ??
karl
[ June 11, 2004: Message edited by: karl koch ]

[john von]

Is there no shortcut to it?
What if i re-initialize it?

String[] names = new String[5]
for(int i=0; i<=4; i++)
{
 names[i] = "joe"+i;
 names = new String[5]; // emptied the array names???
}

It the array "names" was not emptied through re-initialization, what will happen to the previous object "names" after it was re-intialize?

[fred rosenberger]

you haven't really "emptied" the original array, you've created a second, new empty array and pointed your reference to it.

the first one is still there, but you can't get to it ever again. it will eventually be garbage-collected - although you have NO control over when that is done.

[Ernest Friedman-Hill]

Note that another alternative (a better one, IMO) to the array-emptying "for" loop is to use the overloaded static "fill" methods in the java.util.Arrays class:

String[] s = {"foo", "bar"};
Arrays.fill(s, null);
System.out.println(s[0] + ", " + s[1]);

prints "null, null".

[john von]

Thanks. I have a follow up question, but ill just create a new thread.

Thanks again!