syntax

问题 If I run the following code Sub Test_1() Cells(1, 1).ClearContents Cells(2, 1).Value = "" End Sub When I check Cells(1, 1) and Cells(2, 1) using formula ISBLANK() both results return TRUE . So I'm wondering: What is the difference between Cells( , ).Value = "" and Cells( , ).ClearContents ? Are they essentially the same? If I then run the following code to test the time difference between the methods: Sub Test_2() Dim i As Long, j As Long Application.ScreenUpdating = False For j = 1 To 10 T0

问题 I see these used interchangeably. What's the difference? 回答1: There is no difference. From perldoc perlsyn: The foreach keyword is actually a synonym for the for keyword, so you can use foreach for readability or for for brevity. 回答2: I see these used interchangeably. There is no difference other than that of syntax. 回答3: Four letters. They're functionally identical, just spelled differently. 回答4: Ever since its introduction in perl-2.0, foreach has been synonymous with for . It's a nod to

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: What does this construct mean? I'm encountering this syntax for the first time and am not sure what it's doing: self.name = _searchString(settings.dataBrowser) || "An unknown browser"; What does the or (double pipes) condition do? When would self.name be set to the second value? 回答1: This is the logical or operator. It evaluates to its first "truthy" operand. In particular, it will evaluate to the second operand

问题 This question already has answers here : Closed 8 years ago . Possible Duplicate: What does this construct mean? I'm encountering this syntax for the first time and am not sure what it's doing: self.name = _searchString(settings.dataBrowser) || "An unknown browser"; What does the or (double pipes) condition do? When would self.name be set to the second value? 回答1: This is the logical or operator. It evaluates to its first "truthy" operand. In particular, it will evaluate to the second operand

问题 I am learning to work with some math like PHP query and just got to the modulo, I am not quite sure in what situations to use this because of something i stumbled on and yes I did already read one of the posts here about the modulo : Understanding The Modulus Operator % (This explanation is only for positive numbers since it depends on the language otherwise) The quote above is in the top answer there. But if I focus on PHP only and i use the modulo like this: $x = 8; $y = 10; $z = $x % $y;

问题 I'm trying to understand the relations between pair , cons , dotted tuples and proper list in PLT-Scheme 372. The detailed context of my question is as follows: After reading some textbook and doing trial-and-error, I have got the following understanding and intuitive ideas (I may be wrong...): all lists are pairs, e.g.: (pair? (list 'a 'b 'c)) => #t all conses are pairs, e.g.: (pair? (cons 'a (cons 'b 'c))) => #t some dot-separated tuples are pairs, e.g.: (pair? '(a . b)) => #t (pair? '(a .

问题 This is probably super trivial, but I can't find any information about what the ':>' symbol means in Coq. What is the difference between: U : Type and W :> Type ? 回答1: It depends on where the symbol occurs. If it is inside a record declaration, for instance, it instructs Coq to add the corresponding record projection as a coercion. Concretely, suppose that we have the following definition of a type with an operation: Record foo := Foo { sort :> Type; op : sort -> sort -> sort }. We can now

问题 I recently posted a question about getting last 3 results in table in the correct order. I now want the get all comments apart from the last 3 in the correct order. Here is my syntax; SELECT * FROM (SELECT * FROM $table ORDER BY ID DESC OFFSET 3) AS T ORDER BY TIME_STAMP The error I am receiving is: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'OFFSET, 3) AS T ORDER BY TIME_STAMP' at line 1 I can't seem

问题 I found this code in a book: function foo() { console.log( this.a ); } var a = 2; var o = { a: 3, foo: foo }; var p = { a: 4 }; o.foo(); // 3 (p.foo = o.foo)(); // 2 What does last line mean? 回答1: The last line is doing an assignment and then calling the function. Assignment happens first (p.foo = o.foo) Then call the function (p.foo = o.foo)(); In this second call to foo, it is being called outside of the scope of p or o, so it's essentially the same as calling: foo(); 来源： https:/

问题 I am trying to use this query in a Filemaker -> MySQL transition script. The table creation steps are taken directly from a phpMyAdmin export, and I added in the DROP statements. DROP TABLE IF EXISTS artifacts; CREATE TABLE IF NOT EXISTS `artifacts` ( `aid` INT(11) UNSIGNED NOT NULL auto_increment, `accession number` TEXT NOT NULL, `name` TEXT NOT NULL, `period 1` TEXT NOT NULL, `period 3 date` TEXT NOT NULL, `visual description` TEXT NOT NULL, `religion 1` TEXT NOT NULL, `dimen 1 number`