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Differences in boolean operators: & vs && and | vs ||
...)){
}
"Short-circuiting" means the operator does not necessarily examine all conditions. In the above examples, && will examine the second condition only when a is not null (otherwise the whole statement will return false, and it would be moot to examine following conditions anyway), so th...
WebView and HTML5
...ient object.
@Override
public void onShowCustomView(View view, CustomViewCallback callback) {
super.onShowCustomView(view, callback);
if (view instanceof FrameLayout){
FrameLayout frame = (FrameLayout) view;
if (frame.getFocusedChild() instanceof VideoView){
Vide...
Difference between Git and GitHub
... Also, you don't have to use a remote service like github if all you want is version control - local git is just fine for that. Remote repositories are for backup and collaboration.
– Thilo
Nov 10 '12 at 11:42
...
How to use NULL or empty string in SQL
...pty string. REASON: if there is ONLY whitespace, a single trim will remove all of it. For example, you don't care whether the comparison fails because what remains is "abc" or " abc".
– ToolmakerSteve
Dec 9 '16 at 20:06
...
What is an idempotent operation?
...ng, an idempotent operation is one that has no additional effect if it is called more than once with the same input parameters. For example, removing an item from a set can be considered an idempotent operation on the set.
In mathematics, an idempotent operation is one where f(f(x)) = f(x). For exa...
How to change the Content of a with Javascript
...extarea" name="something">This text gets removed</textarea>
For all the downvoters and non-believers:
Here's the MSDN reference
value Property: Retrieves or sets the text in the entry field of the textArea element.
Here's the MDN reference
value DOMString The raw value cont...
Most efficient conversion of ResultSet to JSON?
...tests. You could probably make it more elegant with a HashMap lookup to a callback but I doubt it would be any faster. As to memory, this is pretty slim as is.
Somehow I doubt this code is actually a critical bottle neck for memory or performance. Do you have any real reason to try to optimize it?...
What are the rules for JavaScript's automatic semicolon insertion (ASI)?
...
First of all you should know which statements are affected by the automatic semicolon insertion (also known as ASI for brevity):
empty statement
var statement
expression statement
do-while statement
continue statement
break statement...
Warning message: In `…` : invalid factor level, NA generated
...
Here is a flexible approach, it can be used in all cases, in particular:
to affect only one column, or
the dataframe has been obtained from applying previous operations (e.g. not immediately opening a file, or creating a new data frame).
First, un-factorize a stri...
Fluent Validation vs. Data Annotations [closed]
...when used for ASP.NET MVC validatation? They seem to have similar objects, all the way to their object names. Is one related to another? What are their differences? In what way do these differences denote different use cases?
...