Function is a block of code which performs a specific task.

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Please let me know more refactoring strategies for my codebase?

I have written a shell command-line interpreter which uses loops and recursion (but maybe not "recursive decent", that usually solves this problem) I want to refactor the function to 4 or 5 smaller ...
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3answers
79 views

Design for a function to skip a step if called multiple times

Terrible title, but this is the situation I find myself in often and have not found a good design to make it nice. Lets say I'm working with Javascript and I have an object I am working on that needs ...
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4answers
225 views

When should a function take a pointer for a collection to fill vs returning a pointer with a filled collection?

In C++ I frequently see these two signatures used seemingly interchangeably: void fill_array(Array<Type>* array_to_fill); Array<Type>* filled_array(); I imagine there is a subtle ...
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1answer
117 views

Returning a variable or a return code from a function

Let assume that we have a main() function in which we call a createDirectory() function. In Python for instance, the code would be: def main(): # Do some stuff createDirectory(myPath) # ...
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2answers
58 views

Cleanly generating several 0-airty JavaScript functions with slightly different bodies

Say I have a bunch of JavaScript functions similar to: message = [“000”, “111”, “222”, “333”]; function F0(){ alert (message[0]); } function F1(){ alert (message[1]); } function F2(){ ...
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1answer
58 views

Multiple arguments for last parameter

I have function that has three parameters, called key, value and attribute. Parameter attribute may be empty or have within two arguments. Code of function below is shortened (deprived of arguments ...
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2answers
327 views

Differences between “first-class function” mechanisms

Some languages (Javascript, Python) have the notion that a function is an object: //Javascript var fn = console.log; This means that functions can be treated like any other object (first-class ...
4
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1answer
133 views

Is there a programming language which requires argument qualifiers (reference/value) to be specified at the call point?

For quite a long time now, I have been using a calling convention from C++ google style guide, which boils down to the following: "[for a function] arguments are values or const references while ...
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3answers
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Is a function getting a value from another function considered pure?

I'm trying to figure out a way to handle default variable values when making functions without side effects and have ended up with the following: function getDefaultSeparator() { return ':'; } ...
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2answers
1k views

Why is passing large anonymous functions as arguments to other functions so widely accepted in JavaScript?

I have an opinion (which I am sure will be shared by some) that passing anonymous functions which contain more than a few lines of code, as arguments to other functions affects readability and ...
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3answers
198 views

Is it considered good practice to always have methods return a value?

Sorry for the terrible title but hopefully these snippets will give you the gist. Method 1: class Person: def __init__(self, name): self.name = name def set_name(self, new_name): ...
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4answers
131 views

How to name functions that use conditionals in refactoring [closed]

Consider this bit of code : private Norf foo(Baz baz) { // ... // Logic on baz // ... if (baz.color == Baz.BLUE) { // Do this thing } // ... // More logic // ...
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1answer
129 views

Enumerating the primitive recursive functions

How can I enumerate (by expression tree size, for example) all of the primitive recursive functions that map natural numbers to natural numbers in a traditional programming language like C? For ...
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1answer
125 views

Why use tuples as function parameters in languages that support currying?

In languages that support currying, I can't think of many cases where using a tuple as function input parameters would be better than breaking the tuple apart into multiple parameters, which then ...
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2answers
53 views

“Separate Query from Modifier” and return values [closed]

I've heard it said that you should keep query and modifier functions separate from one another, and I agree with the sentiment. When trying to apply it, I often run into two issues/questions: What, ...
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4answers
323 views

Swift functions vs computed properties

Say I have have a class Event as follows: class Event { private var attendees: [Person] = [] // Case 1 //******* // Should I use a func… func countOfAttendees() -> Int { ...
0
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1answer
126 views

How to document **kwargs in python? [closed]

I have a function which has a large number of arguments. I want to have the names of the arguments available in the help() function, but I want the results as a dict. At the moment, I have the ...
2
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2answers
232 views

Java - Using a Function variable to set the toString() method's return value

Lately I've started adding this to certain classes in an in-house API: public class MyClass { // I usually do this with classes I expect to // be printed out or tested a lot (particularly // ...
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1answer
101 views

Reducing the arity of functions [closed]

I have discovered that reducing the arity of functions in my code to zero or one improves their non-functional characteristics significantly, such as testability, maintainability and their ...
0
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1answer
118 views

Function or class design in library API for efficient object reuse

I am currently building a library in C++11, where I spent a lot of time trying to design a good interface. After some small redesigns along the way, I've ended up with a design that I am happy with. ...
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3answers
511 views

Functions whose parameters are implicitly supplied

Callback functions are able to accept some parameters, but they are not explicitly declared when calling the function. How does this actually work? What is going on that allows us to pass a function ...
5
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2answers
212 views

What is the difference between currying and partial function application in practice

I understand the difference between partial function application and a curried function (f(X x Y x Z) -> N vs f(X -> (Y -> (Z -> N)))), but I do not see what the consequence of this ...
3
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1answer
417 views

What does comma signify in a function definition?

From PHP manual: array array_change_key_case ( array $array [, int $case = CASE_LOWER ] ) What does comma signify in a function definition?
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1answer
169 views

Function name in parentheses after fuction call in Python

I ran into these lines of code in the QPYTHON Android app. They are part of a sample that uses the Bottle module to create a simple Web server that seems to work fine. app = Bottle() app.route('/', ...
2
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2answers
184 views

What's wrong about extending a class with prototype methods?

I was at a bar last night with a few of my colleagues. They said that it's a bad idea to extend the functionality of basic JavaScript Objects with a prototype method. For example, let's say you ...
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2answers
63 views

problems compiling a function with a trait Add in Rust [closed]

I'm trying to write a generic function summ in rust - but to no avail. Could someone please elucidate the problem? fn summ<T:Add>(a:T,b:T)->T { a+b }
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1answer
172 views

Const and non-const methods, and possible mutable data member?

I'm working on a design and implementation change due to a bug. The bug fix requires us to modify a class object in a const method. I think the two options are: Have the non-const method cast this ...
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4answers
166 views

How can Guard Statements and Small Functions coexist?

By Guard Statements I mean something similar to the first part of the function: def doSomething(String something) { // Guard Statement if(!something) { return false } // ...
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2answers
109 views

Are there constraints for functions in structured programming?

I just talking with a colleague (University instructor) who teaches C (Fundamental of programming Course). He said I won't give score to a student, if he uses I/O (scanf or printf or cin count) in a ...
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2answers
182 views

Haskell types for functions

I don't understand the answer to this question: Q: Can Haskell find a type for the function selfapply defined by: selfapply f = f f A: The function selfapply is not typeable in the simple ...
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2answers
159 views

Is there a approximate string comparison function which is odd like mathematical functions are odd?

I say odd like a mathematical function, a mathematical function is odd if f(-x) = -f(x) I understand that comparing two strings may seem to have little to do with this, because the arguments cannot ...
0
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1answer
300 views

Setting up folders and importing modules in Python

I'm building an app to automate some processes that are annoying to do by hand (looking in a file, taking certain information out of a file, building another file with that information). My project ...
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1answer
136 views

When should one create a new py-function rather than tweaking another one?

Me and a co-developer are arguing when it's wise to cast a new function rather than tweaking another one. By tweaking I mean an option or a hidden check in an existing function. The question could be ...
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2answers
236 views

Are any side effects not concrete side effects?

In Chapter 23 of "Object Oriented Software Construction" (1988), Betrand Meyer makes a distinction between side effects, concrete side effects, and abstract side effects. Meyer defines a side effect ...
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5answers
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Method extraction vs underlying assumptions

When I split big methods (or procedures, or functions — this question is not specific to OOP, but since I work in OOP languages 99% of the time, it's the terminology that I'm most comfortable with) ...
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3answers
410 views

How are basic functions implemented in a programming language if they are not built in? [closed]

The lowest levels of a programming language's library functions are always obscure and often have no code that looks like it even remotely does anything. Some languages have these functions like ...
0
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1answer
148 views

Can i create a function with variable parameters in C?

I've always wondered where a single function such as printf(); can take in variable parameters and provide the right results. For example, printf("Number is %d",a); which has two parameters, and ...
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2answers
59 views

Function that would output all distinct values in an array

I want to create a function that outputs the distinct values in a given array. For example, in the following sequence 2 2 1 1 5 2 , the distinct digits are 2 1 5. What I've done till now is: void ...
31
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1answer
2k views

Name for a Function which Returns its Arguments?

A function that does nothing, takes no arguments and returns nothing is traditionally called a noop, or no-op. An example of a noop is below: function noop(){} http://en.wikipedia.org/wiki/NOP So ...
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5answers
411 views

Should private functions be held to the same standards as public functions?

If I'm building private utility functions, should they be held to the same rigorous standards in terms of handling invalid data as public functions? Example:If I'm writing code to calculate the ...
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3answers
350 views

What is the difference between a helper and a convenience function?

The title and the question are the same! The two seem the same to me: a convenience is a helper. A helper is a convenience. So when is it good to use the one or the other term?
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5answers
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When, if ever, should I daisy chain functions?

I'll try to be as brief as possible in respect to your time. In a program divided up into many functions by which it is intended that they execute themselves one after another, when (if ever) is it ...
0
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1answer
2k views

Python: Faster to use global variable or pass as arguments to a function? [duplicate]

Hey so i was wondering which is the more efficient way, or better practice to do in this situation. 1, def function(): global number number += 2 Or 2, def function(number): return ...
0
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2answers
69 views

Iterating a function with a static argument: Global functions + lambdas vs internal function?

I am never sure which of these is better form: Option A def a(x,y): def b(z): return z+y return map(b, x) print a([10,20], 5) Option B def b(z,y): return z+y def a(x,y): return ...
3
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2answers
145 views

Strategies for parameter wrapping

Methods with many parameters are often sometimes unavoidable. In my own experience I often find this is the case for program entry points and complex mathematical procedures - where refactoring is ...
8
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4answers
2k views

why empty function are needed

I started learning python and I am wondering why empty function are needed in a programming language e.g. in python: def empty_func(): pass even in shell scripts empty function empty functions ...
4
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4answers
2k views

int * vs int [N] vs int (*)[N] in functions parameters. Which one do you think is better?

When programming in C (or C++) there are three different ways to specify the parameter in a function that takes an array. Here is an example (implementing std::accumulate from C++ in C) that shows ...
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Why is *declaration* of data and functions necessary in C language, when the definition is written at the end of the source code?

Consider the following "C" code: #include<stdio.h> main() { printf("func:%d",Func_i()); } Func_i() { int i=3; return i; } Func_i() is defined at the end of the source code and ...
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1answer
72 views

Are there defined standards for argument sequence? [closed]

Say I have a function taking three arguments: a symbol (an alias for a class, method or function name) a mirror/reflection of a specific object a mirror/reflection of a class in general is there a ...
3
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3answers
308 views

When is inlining worth it?

Modern compilers often inline functions when they decide it is worth it. But here comes my question: how does one define if it is optimal to inline function at given time, or more important how to ...