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

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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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1answer
94 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 system of ...
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2answers
138 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 ...
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1answer
58 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
75 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
217 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
1k views

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
336 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 ...
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1answer
94 views

Is there is a way to pass more than one value to the calling function in c++? [closed]

I'm new at computer science and programming, Can any one give me a hand to know "Is there is a way to pass more than one value to the calling function in c++". Explain how?
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1answer
136 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
47 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 ...
30
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1answer
1k 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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3answers
83 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
612 views

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 ...
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1answer
385 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 ...
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2answers
45 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 ...
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2answers
109 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 ...
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4answers
359 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 ...
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4answers
462 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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5answers
2k views

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 ...
1
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1answer
65 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
292 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 ...
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0answers
16 views

Hidden event handlers and their parameters

I'm having a bit of trouble understanding why has an event handler to be defined as a function. AFAIK, a function can be used as anonymous called procedure as event handler It defines a ...
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2answers
106 views

memory needed to store a function in javascript

I have been using sizeof.js to investigate the size of various objects in javascript. It appears from this that the size of a function is essentially zero bytes, regardless of how many instructions ...
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2answers
168 views

How does the CPU access the values of stack-allocated variables? [duplicate]

Consider the following C++ function: void doStuff() { Thing thingA; Thing thingB; thingA.doSomething(); // .. etc } During the execution of this function, variables thingA and ...
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8answers
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What is the benefit of a function without parameters which only calls another function

A tutorial (for Javascript) I'm doing suggests we write a function like this one: function sayHello() { //Some comments explaining the next line window.alert("Hello"); } Other than ...
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12answers
4k views

Why do most programming languages have special keyword or syntax for declaring functions? [closed]

Most programming languages (both dynamically and statically typed languages) have special keyword and/or syntax that looks much different than declaring variables for declaring functions. I see ...
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2answers
132 views

Is there a way for Object 1 to call Object 2's enums in a function call?

For example, if I have two classes "Director" and "Follower". I want the Director to tell the follower where to go (ex: follower1.go(direction.LEFT)), and I want the Director to know what directions ...
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1answer
90 views

Why does this function work even though the vars are different

$inumber1 = 10; $inumber2 = 20; function add($number1, $number2) { echo $number1 + $number2; } add($inumber1, $inumber2); I'm learning PHP coding for the first time and I'm ...
2
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1answer
358 views

How do multiple levels of inheritance affect virtual function call overhead in C++?

I am considering using a class hierarchy with more than a single level of inheritance, where virtual member functions form a "chain", for example: struct Base { virtual void foo(); }; struct D1 : ...
0
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1answer
98 views

How to split a Service class in two but still use them like one?

I've got a class: AuthenticationService findLoggedInUser() Checks session if User is logged in. If not, check client persistent user login cookie and log in. loginUser($email, $pw, $remember = ...
14
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7answers
2k views

Function only returns unchanged parameter, useless?

I just found this function in the project I'm working at: -- Just returns the text unchanged. -- Note: <text> may be nil, function must return nil in that case! function Widget:wtr(text) ...
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9answers
4k views

Beginning a sentence with a function name? [closed]

Occasionally while typing something up that relates to a case-sensitive programming language I end up starting a sentence with a function name. Now the rules of English state that the first word in a ...
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1answer
313 views

Does this function do one thing only?

Is the following method considered to be doing one thing only? I'm wondering about that since it takes an optional argument. public function findErrors($name = null) { if ($name) { ...
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4answers
562 views

Are first-class functions a substitute for the Strategy pattern?

The Strategy design pattern is often regarded as a substitute for first-class functions in languages that lack them. So for example say you wanted to pass functionality into an object. In Java you'd ...
28
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8answers
5k views

Is splitting up a function into several inner functions an anti-pattern? [duplicate]

Imagine a long and complicated process, which is started by calling function foo(). There are several consecutive steps in this process, each of them depending on result of the previous step. The ...
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2answers
117 views

Should you avoid adding unecessary stack frames?

I have been working with laravel (PHP) recently, and there is an option when using their fluent ORM to define where clauses using closures. This gives us two, functionally equivalent, ways to specify ...
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2answers
170 views

Property or Method to obtain information about a collection?

Suppose I have a MyList class which extends ObservableCollection<MyObject> where MyObject has the Boolean Property Enabled. Let's say I want the number of MyObject objects that have the ...
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3answers
176 views

Use of malloc in C

Is it necessary to call free function every time we use malloc in C. I am asking this because I have seen many times that it is not called . Thank you
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1answer
254 views

static or non-static, that is the question? [duplicate]

For comparisons / evaluations of objects of the same class(and other purposes), is it better to define a static or a non-static (is this called "dynamic" by chance?) function? Sample code: class ...
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2answers
187 views

What is the concept behind writing a cancel operation in c++? [closed]

I'm attempting to write a cancel operation for a software download application. This application will first transfer the software to the device and then install the software on it. (These are givens ...
0
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3answers
141 views

Writing a method to 'transform' an immutable object: how should I approach this?

(While this question has to do with a concrete coding dilemma, it's mostly about what's the best way to design a function.) I'm writing a method that should take two Color objects, and gradually ...
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2answers
1k views

Why are there no function pointers in Java? [closed]

Lately I started studying about different interesting concepts that exist in languages other than Java. Since the only language I've ever programmed with is Java, a lot of these concepts are very new ...
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3answers
210 views

Reason to treat internal class variables and functions inside a class as “separate” entities

Note: there is a similar question that addresses my subject: Better style for member variables? ... but that question does not address "dealing with large legacy code base and comprehension of ...
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1answer
125 views

Use Generic of Specific Function names for similar objects

Is there a school of thought on putting focus on using generic names for functions, opposed to naming functions based on the things they do? Example Say we have a Bill / Price Sheet object, that has ...
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6answers
725 views

Are closures considered impure functional style?

I have a few related questions on closures: Are closures considered impure in functional programming? It seems one can generally avoid closures by passing values directly to a function. Therefore ...
2
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1answer
123 views

How to simplify unit testing with higher order functions?

this is not a question on how to write unit tests this is not a question on what to test this is a question on reducing the typing needed overall for a personal testing framework I know you can ...
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4answers
109 views

To make a class function or not?

I'm wondering about functions used like this: object1->objectMethod1(arg1, arg2); if objectMethod1: - does not change the object state - does not use the object's state at all - is used by the ...
2
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3answers
241 views

Using past participle for non-altering functions [closed]

I often have naming problems when I write classes and functions. Generally speaking, I try to follow the following set of rules if I have to deal with a function whose name is a verb: If the ...
2
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3answers
317 views

Does designing a method that changes the argument's (if was object) values a good practice?

The premise is using a language (e.g. C#, javascript) which passes an object by reference into a method. Assume there is an object "Player" which has a property "Level" and there is a method takes ...