function

问题 I have a situation where I need to enforce and give the user the option of one of a number of select functions, to be passed in as an argument to another function: I really want to achieve something like the following: from enum import Enum #Trivial Function 1 def functionA(): pass #Trivial Function 2 def functionB(): pass #This is not allowed (as far as i can tell the values should be integers) #But pseudocode for what I am after class AvailableFunctions(Enum): OptionA = functionA OptionB =

问题 I'm trying to create a function for my project. I would like it to handle all the check functions. What I mean with that is before you start inserting a row in your database you check if a row exists with that email address. To use this function dynamically it needs to be flexible. So I did put my variables in an array, but mysqli_stmt_bind_param can't handle arrays. As a solution, I tried making a foreach loop. The query: $sql = "SELECT users_id, users_email FROM users WHERE users_id = ? AND

问题 I have the following Python code: data = ['1', '4.6', 'txt'] funcs = [int, float, str] How to call every function with data in corresponding index as an argument to the function? Now I'm using the code: result = [] for i, func in enumerate(funcs): result.append(func(data[i])) map(funcs, data) don't work with lists of functions ( Is there builtin function to do that simpler? 回答1: You could use zip* to combine many sequences together: zip([a,b,c,...], [x,y,z,...]) == [(a,x), (b,y), (c,z), ...]

问题 The manual entry of one of the following numerical values ​​will be entered in cell "AC1": 1; 2; 3; 4 or 5. Each of them represents a range of cells that will take priority among all the others. Each of the cells in the range "A2:A86" contains a function with a similar structure: = ‘SheetX’AX! . For example: = ‘Sheet1’B4! ; = ‘Sheet2’B4! ; = ‘Sheet6’B4! ; etc. The ranges of cells that form groups are: Range 1 = "A2:A18"; range 2 = "A19:A35"; range 3 = "A36:A52", range 4 = "A53:A69"; and range

问题 This question already has an answer here : How to create cron jobs in firebase programmatically (1 answer) Closed 14 days ago . Does anyone know how can I set up Cron Jobs dynamically with Firebase? I want to build a rule engine using which the Client can specify the rules, actions, and schedule and based on that I need to schedule that particular rule. Since the scheduling is in the hand of the Client. I can set a predefined frequency for the JOB. I know in Node.js I can do it with libraries

问题 I am a beginner in JS and working at a shopping cart. I have several products which are rendered in the page with ES6 template strings. Everything is working so far, you can add items to the basket and the basket and total update correctly. The only part I am having trouble with is the increase/decrease buttons: they only work once, if you click again the amount printed in the console stays the same. I did find other SO post related to increment/decrement functions but the button keeps

问题 I think my question can be made quite generic and simple, so that I will not give the concrete function that I am trying to make. I have a function that changes its behaviour according to its first argument: example <- function(arg1 = T, arg2 = NULL, arg3, ...) { if (arg1 != T) { final <- bind_rows(arg2) } else{ list1 <- list(...) final <- bind_rows(list1, arg3) } return(final) } My issue is that if I run example(arg1 = T, arg3 = x, c(A,B), c(C,D)) , considering that the user of my function

问题 I'm trying to write a loop that calculates power without using the pow() function. I'm stuck on how to do that. Doing base *= base works for even powers upto 4, so there is something totally weird that I can't seem to figure out. int Fast_Power(int base, int exp){ int i = 2; int result; if(exp == 0){ result = 1; } if(exp == 1){ result = base; } else{ for(i = 2; i < exp; i++){ base *= base; result = base; } } return result; } 回答1: First off, I agree it was probably a mistake to use base *=

问题 Say, something like this: int SayHelloThenReturnTen(void) { puts("Hello world"); return 10; } Then later: ((void(*)(void))SayHelloThenReturnTen)(); Is that safe? Is it safe to "trash" the return value by casting to a void pointer? Is this safe and cross platform, or is this undefined behavior ? 回答1: Is that safe? It is safe to cast a function pointer to any function pointer type. Casting the result back to the original type will yield a pointer value equal to the the original pointer. It is

问题 This is a follow up to my earlier question. I wanted to compare the results I get back from filling out a form. This is what I have so far: const eqObj = (obj, source) => Object.keys(source).every(key => obj.hasOwnProperty(key) && obj[key] === source[key]); $('#btn').on('click', function() { let $inputs = $('#new_form :input'); let new_vals = {}; $inputs.each(function() { new_form[this.id] = $(this).val(); }); console.log(new_vals); $.getJSON(api, function(data) { data.forEach(d => { console