In Java, I want to delete certain elements from a char array so it does something like:
char[] Array1 = {'h','m','l','e','l','l'};
Array1 = //character index[2] to character index[5]
How can this be done?
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5 Answers
In Java you can't delete elements from an array. But you can either:
Create a new char[] copying only the elements you want to keep; for this you could use System.arraycopy() or even simplerArrays.copyOfRange(). For example, for copying only the first three characters of an array:
char[] array1 = {'h','m','l','e','l','l'};
char[] array2 = Arrays.copyOfRange(array1, 0, 3);
Or use a List<Character>, which allows you to obtain a sublist with a range of elements:
List<Character> list1 = Arrays.asList('h','m','l','e','l','l');
List<Character> list2 = list1.subList(0, 3);
1 Comment
user1516514
how do u copy certain elements coz i want: 'code'(char[] example = //first character to 3rd last.) is there a range method or something?
Java function to remove a character from a character array:
String msg = "johnny can't program, he can only be told what to type";
char[] mychararray = msg.toCharArray();
mychararray = remove_one_character_from_a_character_array_in_java(mychararray, 21);
System.out.println(mychararray);
public char[] remove_one_character_from_a_character_array_in_java(
char[] original,
int location_to_remove)
{
char[] result = new char[original.length-1];
int last_insert = 0;
for (int i = 0; i < original.length; i++){
if (i == location_to_remove)
i++;
result[last_insert++] = original[i];
}
return result;
}
The above method prints the message with the index 21 removed. You could place this in a loop to remove multiple items. Technically you are not deleting an item, you are creating a brand new char array with the item removed. You have to step through the entire string for each remove which is very inefficient.
Delete a character by index from a character array with StringBuilder in Java:
String mystring = "inflation != stealing";
char[] my_char_array = mystring.toCharArray();
StringBuilder sb = new StringBuilder();
sb.append(mystring);
sb.deleteCharAt(10);
my_char_array = sb.toString().toCharArray();
System.out.println(my_char_array); //prints "inflation = stealing"
The above code removes the exclamation mark from the character array. If you want to delete a RANGE of characters, use sb.delete(10, 15);
1 Comment
Geoff Langenderfer
how could we do this with O(1) space?
You can use this method:
public static char[] copyArray(char[] original, int start, int length)
{
char[] result = new char[length];
for (int i = 0; i < length; i++)
{
result[i] = original[start + i];
}
return result;
}
1 Comment
Paul Bellora
Or you could use
Arrays.copyOfRange(char[], int, int).Yes, you can use Arrays.copyOfRange(char[], starting index, ending index) method for you.
You can also view this --
