Possible Duplicate:
Removing an element from an Array (Java)
How to remove specific String array value for example
String[] str_array = {"item1","item2","item3"};
i want to remove "item2" from str_array pls help me i want output like
String[] str_array = {"item1","item3"};
I would do it as follows:
String[] str_array = {"item1","item2","item3"};
List<String> list = new ArrayList<String>(Arrays.asList(str_array));
list.remove("item2");
str_array = list.toArray(new String[0]);
System.arraycopy, especially when used multiple times.
If you must use arrays, System.arraycopy is the most efficient, scalable solution. However, if you must remove one element from an array several times, you should use an implementation of List rather than an array.
The following utilizes System.arraycopy in order to achieve the desired effect.
public static Object[] remove(Object[] array, Object element) {
if (array.length > 0) {
int index = -1;
for (int i = 0; i < array.length; i++) {
if (array[i].equals(element)) {
index = i;
break;
}
}
if (index >= 0) {
Object[] copy = (Object[]) Array.newInstance(array.getClass()
.getComponentType(), array.length - 1);
if (copy.length > 0) {
System.arraycopy(array, 0, copy, 0, index);
System.arraycopy(array, index + 1, copy, index, copy.length - index);
}
return copy;
}
}
return array;
}
Also, you can increase the method's efficiency if you know that your array consists of only Comparable objects. You can use Arrays.sort to sort them before passing them through the remove method, modified to use Arrays.binarySearch to find index rather than a for loop, raising that portion of the method's efficiency from O(n) to O(nlogn).
Object[] back when you want a String[]. Array.newInstance lets you construct an array of arbitrary type.Array.newInstance might be slower, but it is not necessarily so. HotSpot can optimize it to be just as fast as a regular array instantiation in most cases. Either way, you end up with a more robust and correct program.Other Option is to copy array to other array accept than remove item.
public static String[] removeItemFromArray(String[] input, String item) {
if (input == null) {
return null;
} else if (input.length <= 0) {
return input;
} else {
String[] output = new String[input.length - 1];
int count = 0;
for (String i : input) {
if (!i.equals(item)) {
output[count++] = i;
}
}
return output;
}
}
item from the input array rather than just one.