大约有 31,500 项符合查询结果（耗时：0.0525秒） [XML]
How to assign from a function which returns more than one value?
...eturningTwoValues()
If you only need the first or second component these all work too:
list[a] <- functionReturningTwoValues()
list[a, ] <- functionReturningTwoValues()
list[, b] <- functionReturningTwoValues()
(Of course, if you only needed one value then functionReturningTwoValues()[...
Immutability of Strings in Java
...t, and changing a reference. s2 still points to the same object as we initially set s1 to point to. Setting s1 to "Help!" only changes the reference, while the String object it originally referred to remains unchanged.
If strings were mutable, we could do something like this:
String s1 = "Hello";
St...
Windows 7 SDK installation failure
I seem to be completely unable to install the Windows 7 SDK onto my machine, and the only solution I've found on the web is to make a swathe of registry changes. I've done this - still no success.
...
What are valid values for the id attribute in HTML?
...
For HTML 4, the answer is technically:
ID and NAME tokens must begin with a letter ([A-Za-z]) and may be followed by any number of letters, digits ([0-9]), hyphens ("-"), underscores ("_"), colons (":"), and periods (".").
HTML 5 is even more permissiv...
CSS selector by inline style attribute
...will stop matching values that don't contain the space, unless you include all the permutations, ad nauseum. But if you're working with a document in which the inline style declarations themselves are unlikely to change at all, you should be fine.
Note also that this is not at all selecting element...
How to call a parent method from child class in javascript?
...Here's how its done: ParentClass.prototype.myMethod();
Or if you want to call it in the context of the current instance, you can do:
ParentClass.prototype.myMethod.call(this)
Same goes for calling a parent method from child class with arguments:
ParentClass.prototype.myMethod.call(this, arg1, arg2...
Reverse a string in Python
...
@Tanner [::-1] is fastest because it does not call any external functions, rather it's using slicing, which is highly-optimized in python. ''.join(list(reversed(s))) makes 3 function calls.
– hd1
Apr 27 at 13:51
...
How do arrays in C# partially implement IList?
...ional, zero-based arrays, as far as the language is concerned, the array really does implement IList<T> too. Section 12.1.2 of the C# specification says so. So whatever the underlying implementation does, the language has to behave as if the type of T[] implements IList<T> as with any ot...
Why can a function modify some arguments as perceived by the caller, but not others?
...
Some answers contain the word "copy" in a context of a function call. I find it confusing.
Python doesn't copy objects you pass during a function call ever.
Function parameters are names. When you call a function Python binds these parameters to whatever objects you pass (via names in a ...
Update a column value, replacing part of a string
... clause optimizes the query to only modify the rows with certain URL. Logically, the result will be the same, but the addition of WHERE will make the operation faster.
– Dmytro Shevchenko
Aug 14 '15 at 14:34
...