How to create variable argument methods in Objective-C

What these are called, generally, is “variadic functions” (or methods, as it were). To create this, simply end your method declartion with , …, as in – (void)logMessage:(NSString *)message, …; At this point you probably want to wrap it in a printf-like function, as implementing one of those from scratch is trying, at best. – … Read more

android BluetoothDevice.getName() return null

Finally, i found out the solution: 1.For device connected: Read device name from gatt characteristic of service org.bluetooth.service.generic_access. 2.For device no connected: /** * Get device name from ble advertised data */ private LeScanCallback mScanCb = new LeScanCallback() { @Override public void onLeScan(final BluetoothDevice device, final int rssi, byte[] scanRecord) { final BleAdvertisedData badata … Read more

Remove NULL elements from list of lists

This recursive solution has the virtue of working on even more deeply nested lists. It’s closely modeled on Gabor Grothendieck’s answer to this quite similar question. My modification of that code is needed if the function is to also remove objects like list(NULL) (not the same as NULL), as you are wanting. ## A helper … Read more

check if variable empty

If you want to test whether a variable is really NULL, use the identity operator: $user_id === NULL // FALSE == NULL is true, FALSE === NULL is false is_null($user_id) If you want to check whether a variable is not set: !isset($user_id) Or if the variable is not empty, an empty string, zero, ..: empty($user_id) … Read more

Determine Oracle null == null

You can do the IsNull or NVL stuff, but it’s just going to make the engine do more work. You’ll be calling functions to do column conversions which then have to have the results compared. Use what you have where ((MYCOLUMN=SEARCHVALUE) OR (MYCOLUMN is NULL and SEARCHVALUE is NULL))