I want to add data to an array at runtime, but I'm getting an index out of bound exception.
String addmembers[] = new String[0];
for (int i=0; i<contactClassList.size(); i++) {
MyClass values = contactClassList.get(i);
String name = values.getUsernameEmail();
Boolean isChecked = values.isChecked;
if (isChecked) {
addmembers[addmembers.length] = name;
}
System.out.println("Value of Array===" + addmembers.length);
}
You can't add to an array. Once you've created it, its size is fixed. You'd be better off using an ArrayList, and just calling add.
List<String> newMembers = new ArrayList<String>();
for (MyClass entry : contactClassList) {
if (entry.isChecked) {
newMembers.add(entry.getUsernameEmail());
}
}
System.out.println(newMember.size());
ArrayList is the right data structure for such problem. In case you bound to use array and what you need as a grow-able then use such solutions Most memory efficient way to grow an array in Java?
Don't use Arrays for bit more amount of data. It would be better if you use ArrayList. I want to rectify your mistake and giving you this answer. You have set the String array size as 0 and trying to add elements which is not possible. So declare the array size as what you required, in your above code contactClassList.size()
String addmembers[] = new String[contactClassList.size()];
for(int i=0;i<contactClassList.size();i++){
MyClass values = contactClassList.get(i);
String name = values.getUsernameEmail();
Boolean isChecked = values.isChecked;
if(isChecked){
addmembers[addmembers.length]=name;
}
System.out.println("Value of Array==="+addmembers.length);
As per your code it will sure give you this error because you are initializing array with 0 size.
Instead of this you can use ArrayList or List<T> then you will be able to add dynamically values to it.
So it is batter to use this two instead of array.
Your array addmembers is of size[0] which once created cannot be changed, why don't you use List, as its of dynamic size
List<String> addmembers = new ArrayList<String>();
for(int i=0;i<contactClassList.size();i++){
MyClass values = contactClassList.get(i);
String name = values.getUsernameEmail();
Boolean isChecked = values.isChecked;
if(isChecked){
addmembers.add(name);
}
System.out.println("Value of Array==="+addmembers.length);
}
Something like this will solve your problem.
