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Java List.add() UnsupportedOperationException
...ion supports the add() method.
One common example is the List returned by Arrays.asList(): it is documented not to support any structural modification (i.e. removing or adding elements) (emphasis mine):
Returns a fixed-size list backed by the specified array.
Even if that's not the specific L...
List comprehension in Ruby
...
If you really want to, you can create an Array#comprehend method like this:
class Array
def comprehend(&block)
return self if block.nil?
self.collect(&block).compact
end
end
some_array = [1, 2, 3, 4, 5, 6]
new_array = some_array.comprehend {|x|...
How to check if array element exists or not in javascript?
...
Use typeof arrayName[index] === 'undefined'
i.e.
if(typeof arrayName[index] === 'undefined') {
// does not exist
}
else {
// does exist
}
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...
Do I have to guard against SQL injection if I used a dropdown?
...mple to make sure the posted size is what you expect.
$possibleOptions = array('All', 'Large', 'Medium', 'Small');
if(in_array($_POST['size'], $possibleOptions)) {
// Expected
} else {
// Not Expected
}
Then use mysqli_* if you are using a version of php >= 5.3.0 which you should be,...
Is arr.__len__() the preferred way to get the length of an array in Python?
...tuple = (1,2,3,4,5)
len(my_tuple)
# 5
And strings, which are really just arrays of characters:
my_string = 'hello world'
len(my_string)
# 11
It was intentionally done this way so that lists, tuples and other container types or iterables didn't all need to explicitly implement a public .length()...
java: ArrayList - how can i check if an index exists?
I'm using ArrayList<String> and I add data at specific indices,
how can I check if a specific index exists?
11 Ans...
How to make an array of arrays in Java
Hypothetically, I have 5 string array objects:
4 Answers
4
...
What is an IndexOutOfRangeException / ArgumentOutOfRangeException and how do I fix it?
... equal to the number of elements it contains.
When It Is Thrown
Given an array declared as:
byte[] array = new byte[4];
You can access this array from 0 to 3, values outside this range will cause IndexOutOfRangeException to be thrown. Remember this when you create and access an array.
Array L...
delete vs delete[] operators in C++
...w.
The delete [] operator deallocates memory and calls destructors for an array of objects created with new [].
Using delete on a pointer returned by new [] or delete [] on a pointer returned by new results in undefined behavior.
...
How do I prevent the modification of a private field in a class?
...
You must return a copy of your array.
public String[] getArr() {
return arr == null ? null : Arrays.copyOf(arr, arr.length);
}
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