function

问题 I'd like to get function's address by name. For example, currently I am using dlsym : unsigned long get_func_addr(const char *func_name) { return (unsigned long)dlsym(NULL, func_name); } However, dlsym only works for extern function. It won't work for static function. I know there could multiple static functions with same name in different files. But I need to at least get one static function's address with the name. Sometime static function will be inlned. But it's OK if C file is compiled

问题 In python, is there a way I can use instance variables as optional arguments in a class method? ie: def function(self, arg1=val1, arg2=val2, arg3=self.instance_var): # do stuff.... Any help would be appreciated. 回答1: Try this: def foo(self, blah=None): if blah is None: # faster than blah == None - thanks to kcwu blah = self.instance_var 回答2: All the responses suggesting None are correct; if you want to make sure a caller can pass None as a regular argument, use a special sentinel and test

问题 Im setting up my powershell profile to create aliases of commonly used commands. On Microsoft's documentation it says, if I want to make an alias for a command with parameters, I should make the value of the alias a Function that does that.. However, when I type the name of the function in the command line it works just as well as an alias. In other words, in the above picture, if I typed CD32 it would behave the same as if I typed Go in the command line So my question is: Why do I use

问题 I'm trying to construct this query using Criteria typesafe API: select * from xxx_table xxx where CALC_DISTANCE(xxx.latitude, xxx.longitude, :lat, :lng) < :dist CALC_DISTANCE definded PL/SQL function: FUNCTION calc_distance( pLat1 NUMBER, pLon1 NUMBER, pLat2 NUMBER, pLon2 NUMBER) RETURN NUMBER CriteriaBuilder builder = JpaHandle.get().getCriteriaBuilder(); CriteriaQuery<XXX> criteria = builder.createQuery(XXX.class); Root<XXX> xxxRoot = criteria.from(XXX.class); ParameterExpression<Double>

问题 Below is my mongodb function that is stored in Mongodb. db.system.js.save( { _id: "echoFunction", value : function(x) { return x; } } ) I can call this function in mongo using below query : db.loadServerScripts(); echoFunction(3); Now i want to call this function from PHP 7. and also help with laravel. 回答1: You can use following code snippet from laravel to execute your mongoDB function. $cursor = DB::connection('mongodb')->command(array('eval' => 'echoFunction("4")')); $data = $cursor-

问题 Below is my mongodb function that is stored in Mongodb. db.system.js.save( { _id: "echoFunction", value : function(x) { return x; } } ) I can call this function in mongo using below query : db.loadServerScripts(); echoFunction(3); Now i want to call this function from PHP 7. and also help with laravel. 回答1: You can use following code snippet from laravel to execute your mongoDB function. $cursor = DB::connection('mongodb')->command(array('eval' => 'echoFunction("4")')); $data = $cursor-

问题 I am not able to understand how this addItem() and removeItem() is called without parenthesis in addEventListener('click', addItem) . var addButton = document.getElementById('add'); addButton.addEventListener('click', addItem); var removeButton = document.getElementById('remove'); removeButton.addEventListener('click', removeItem); function addItem(){ console.log('Add Button clicked'); } function removeItem(){ console.log('Remove Button clicked'); } 回答1: Because in this context, addItem is

问题 Stoyan Stefanov says in JavasScript Patterns that: "you need an immediated function to wrap all your code in its local scope and not to leak any variables to the global scope" page 70. Here is his example (function() { var days = ['Sun','Mon']; // ... // ... alert(msg); }()); But surely because days is defined as a var, it will just be functional scope? The only benefit of the immediate function is the function is invoked immediately. There is no scope advantage. Corrcet? 回答1: It's not about

问题 This question already has answers here : How to access a local variable from a different function using pointers? (10 answers) Closed 4 years ago . What happens when a pointer to a local variable is returned by a function? for example int* foo() { int local; int* ptr = &local; return ptr; } will compiler issue a warning or will it compile and produce unexpected results?? 回答1: Similar kind of question has already been asked : Stack Overflow, local pointer There are somethings in C which are

问题 I am trying to define a 2D array, but I want to do it in a function, here is my code: int** createArray( int columns, int rows) { int** array[rows]; for(int i = 0; i < rows; i++) { array[i] = new int*[columns]; } for(int i = 0; i <columns; i++) { for(int j = 0; j < rows; j++) { array[i][j] = 0; std::cout <<array[i][j]; } std::cout<<"\n"; } return *array; } int main() { int **myArray = createArray(3,5); for(int k =0; k < 5; k++) { if( (myArray[0][k] == 0) && (&myArray[1][k] == 0)) /