syntax

问题 Reading "A re-introduction to JavaScript" I noticed something interesting about functions: The name provided to an anonymous function as above is(or at least should be) only available to the function's own scope. Entering some things based on the code in the tutorial at the nodejs prompt I was able to verify that node agrees with the author: function add(foo, bar) { return foo + bar; } add(1, 2); gets me 3, and: var five = (function plus(foo, bar) { return foo + bar; })(2, 3); plus(2, 3);

问题 At times I have a variable that I want to default to something and if something else is set change it to something else. The question is. What is preferred? Setting the default value and then changing it if the condition is met or setting the condition only once depending on the initial check with an added else? Example in code. if x: y = '%s-other' % x else: y = 'some_default' The other option would be. y = 'some_default' if x: y = '%s-other' % x This isn't always an argument passed in to a

问题 I'm new to Angular, and while following along to a tutorial I made a slight change out of habit when writing the module states: .state('sports.medals', { url: '/:sportName', templateUrl: 'sports/sports-medals.html', resolve: { sportService: function($http, $stateParams){ return $http.get('/sports/${ $stateParams.sportName }'); } }, This compiles perfectly fine within the rest of the project, no errors. However, when the call is made to this function, it reads the get contents as one whole

问题 Using the + function on a tuple of two Int64s returns the sum: julia> +((1, 2)) 3 However, using the + function on a variable that references a tuple gives the following error: julia> a = (1, 2) (1,2) julia> +(a) ERROR: MethodError: no method matching +(::Tuple{Int64, Int64}) I'm having trouble understanding why it behaves like this, especially when the following code returns true. julia> typeof(a) == typeof((1, 2)) 回答1: Note that, contrary to what you might think, julia> :(+((1, 2))) :(1 + 2

问题 I have a game I wrote in Actionscript 3 I'm looking to port to iOS. The game has about 9k LOC spread across 150 classes, most of the classes are for data models, state handling and level generation all of which should be easy to port. However, the thought of rejiggering the syntax by hand across all these files is none too appealing. Are there tools that can help me speed up this process? I'm not looking for a magical tool here, nor am I looking for a cross compiler, I just want some help

问题 I have a string a and I would like to split it in half depending on its length, so I have a-front = len(a) / 2 + len(a) % 2 this works fine in the interpreter but when i run the module from the command line python gives me a SyntaxError: can't assign to operator . What could be the issue here. 回答1: You might mistype hyphen and underscore, try a_front = len(a) / 2 + len(a) % 2 来源： https://stackoverflow.com/questions/2697610/python-syntax-error-cant-assign-to-operator-in-module-but-works-in

问题 Perl has a conditional operator that is the same a C's conditional operator. To refresh, the conditional operator in C and in Perl is: (test) ? (if test was true) : (if test was false) and if used with an lvalue you can assign and test with one action: my $x= $n==0 ? "n is 0" : "n is not 0"; I was reading Igor Ostrovsky's blog on A neat way to express multi-clause if statements in C-based languages and realized this is indeed a "neat way" in Perl as well. For example: (edit: used Jonathan

问题 I'm writing a program, and I have the need to SELECT column names by number, rather than by name. That is, say the attributes to my table are: SSN, FirstName, LastName, MiddleName, Address, City, State, Zip How could I select the data just from columns 0 (SSN), 1 (FirstName), 2(LastName), 6 (State) Is there a way to do this without delving into information schema ? 回答1: You should reconsider your design. A table can be changed, it can evolve, column order is very fickle. You should NOT

问题 How do I approach a function echo_tpl that can take 1 parameter of type int or string ,and print it out? 回答1: C doesn't have templates. I think the best you could do is to use an union or to have the functions have different names. The latter way of having different names is the quasi-standard method of doing it (for instance fabs fabsf fabsl , also heavily used by OpenGL which also accounts for the fact C can't overload functions) void echo_tpl_s(char const *string) { /* ... */ } void echo

问题 How do I approach a function echo_tpl that can take 1 parameter of type int or string ,and print it out? 回答1: C doesn't have templates. I think the best you could do is to use an union or to have the functions have different names. The latter way of having different names is the quasi-standard method of doing it (for instance fabs fabsf fabsl , also heavily used by OpenGL which also accounts for the fact C can't overload functions) void echo_tpl_s(char const *string) { /* ... */ } void echo