Variable or scalar is a storage location paired with an associated symbolic name (an identifier), which contains some known or unknown quantity or information referred to as a value.

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-6
votes
4answers
165 views

Java constructor: I can't understand [on hold]

I am learning Java and I have a problem understanding the concept of constructor for the field variables. What is the problem with the following code. It shows "null" as an output. public class ...
2
votes
2answers
212 views

Avoid This Pointer

PROBLEM: this points to different instances at different stages of execution (as it should). But it is not always obvious which instance is that. On the other hand we could minimize the use of this, ...
1
vote
2answers
94 views

What is the use case for shadowing variables?

One of the things the coffeescript programming language is criticized for is its treatment of variable declarations and scope (example). The answers to this question (and the blog I linked to above) ...
-3
votes
3answers
90 views

Best way to handle variables used in a for loop? [duplicate]

From previous experience, I had always thought that, if you are going to use variables inside of a for loop, it was much better to declare them outside of the loop vs. inside the loop itself. I ...
-4
votes
2answers
64 views

Rationale for modern languages implement changeable global variables [closed]

Common sense seems to be that usage of global variables is bad, in particular if they are used as real variables (i.e. changing state; e.g. Why is Global State so Evil?). How does it come then, that ...
2
votes
1answer
140 views

What is internal state and is there a difference between state and internal state

Ok, this question has been asked before, but it's still not clear to me. What exactly is internal state? So far state is clear to me: Functions contain behavior, variables have state, values don't. ...
37
votes
9answers
3k views

Using compound statements (“{” … “}” blocks) to enforce variable locality [duplicate]

Introduction Many "C-like" programming languages use compound statements (code blocks specified with "{" and "}") to define a variables scope. Here is a simple example. for (int i = 0; i < 100; ...
1
vote
2answers
188 views

Should I declare variables at the top of the function for reasons other than the scope rules?

In JavaScript, one should declare all variables at the beginning of the function to mitigate the risk of mistakes related to the fact that the scope of variables is a function. The following code ...
-3
votes
1answer
136 views

grouping variables into a system in C? [closed]

Within C, say I have a number of variables, floats, integers etc, is there a way that I can group them all into one object, lets call it a system, and then create N copies of such an object. Further, ...
1
vote
4answers
112 views

What is the Pythonic convention for working with an object similar to an existing variable? [closed]

I often have an object, like a list or a dictionary, that I want a variation on. I might want a list with each element changed somehow (perhaps with a list comprehension, or could be a complicated ...
2
votes
1answer
120 views

Patterns for sharing context variables between functions

I am looking for ways of passing around a set of contextual variables that are required by functions. As a Python programmer, right now I can see three ways of solving the problem: passing them ...
4
votes
5answers
359 views

What was the reason for the creation of boolean variables?

I found out that some languages like C don't have support for boolean variables and programmers use integers with values of 0 and 1 instead. Is there any specific reason why some languages moved away ...
0
votes
2answers
128 views

The correct way of declaring & instantiating variables ( Javascript ) [duplicate]

I have seen other peoples code and each person has a different way of declaring variables. And I have been told by quite a few people that declaring variables in the Global Scope is wrong. My ...
0
votes
1answer
49 views

Dealing with data containing integer overflow, rollover

I am writing a small matlab function to analyze data from a laser probe. The data to be analyzed is basically: x-data: Position. y-data: Laser (light) intensity. ...
1
vote
1answer
90 views

Best practices for tracking multiple pieces of data in a program

I have a project in C (don't ask why but it needs to be in C), where I need to track multiple pieces of data and commands for different modules. Some actions that the program will take depend on the ...
2
votes
4answers
341 views

Should I check parameter before using it in methods? [duplicate]

I'm going to build some public PHP packages, Following standards is a priority for me. PHP lets users call methods even if they don't pass required parameters to it. My question. Should I check ...
7
votes
4answers
1k views

Is the use of one-letter variables encouraged? [closed]

Is the use of one-letter variables encouraged in Java? In code snippets or tutorials, you often see them. I cannot imagine using them is encouraged because it makes the code relatively harder to read ...
-2
votes
1answer
114 views

How to name variables without plural in a for-each loop? [closed]

How do you name loop variables when the list item is named after something without a plural? For instance (in python): [x for x in sheep]. x is not a great name, but sheep have/has no plural that ...
2
votes
3answers
677 views

In C++, should I ever declare a local variable in the corresponding header?

So for example, I create a class with two functions: foo.h class foo { public: foo(); void bar(); void ey(); bool m_memberBool; bool localBool; // ??? Should I put this here? }; ...
2
votes
1answer
156 views

Python beginner question with Assigning Variables

Coming from C# and now getting my hands dirty with Python. From what I understand, Python is strongly typed: http://stackoverflow.com/questions/11328920/is-python-strongly-typed As stated in the ...
-1
votes
1answer
91 views

How to make variables inherent to an object or system [duplicate]

How can one make variables inherent to an object or system? For example, when creating a web browser, each option that is created for the user to have control over (i.e. how a window opens, if ...
2
votes
0answers
337 views

Var assignment in sequence diagram

I am trying to represent the function below (PHP function/Symfony2) as a sequence diagram using UML 2.0 and Visual Paradigm: private function getVeevaHcpSync($request, $action, $case) { ...
1
vote
5answers
639 views

Are there too many parameters in this constructor? [duplicate]

Check this out: public function __construct( \Magento\Framework\Model\Context $context, \Magento\Framework\View\DesignInterface $design, \Magento\Framework\Registry $registry, ...
0
votes
5answers
326 views

Is it bad form to use the same variable name in different scopes?

Say you have some basic code where similar operations will take place in nearby lexical scopes. Take for example some simple pseudo code: variable = "foo" # Do something with variable if (True) { ...
2
votes
3answers
2k views

What is the difference between a variable and a parameter? [closed]

Its a conceptual question. But I would like to use the right term at the right place. That is why I would like to read some other views on this.
0
votes
1answer
1k 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 ...
7
votes
2answers
571 views

What is best practice to handle whitespaces when letting the user edit the configuration, the name=value pairs?

For instance, you let the user define the notorious path variable. How do you interpret apppath = C:\Program Files\App? This looks like a programming language adopted practice to ignore the white ...
3
votes
1answer
106 views

Creating variables in methods/functions

In how far do we create variables in our methods or functions? Do we only create one when we're using the result of the variable more then one time like this? function someFunction(SomeClass ...
13
votes
5answers
4k 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 ...
18
votes
4answers
3k views

Why do we have to mention the data type of the variable in C

Usually in C, we have to tell the computer the type of data in variable declaration. E.g. in the following program, I want to print the sum of two floating point numbers X and Y. ...
1
vote
3answers
244 views

Member variables vs. State Varaibels? Are they the same? [closed]

I am learning that member variables are to hold the state of an object? Is it their recommended usage? Are all member variables state variables too? or state variables have specific definition and ...
2
votes
4answers
293 views

Overwriting and returning the value of the argument used as conditional of an if statement, inside the same if statement

A simplified example: function logTheColor (color){ if(color == "red"){ color = "The color is red " } else if (color == "yellow") { color = "The color is yellow " } else { ...
0
votes
2answers
282 views

Prime symbol in Python variable name

So I'm a terrible person and I want to name a variable in my mathy-python3 code s′ (that's a prime symbol). I was under the impression Unicode literals work as identifiers in Python 3, which is why ...
0
votes
1answer
285 views

Is there a way to prevent variables from changing their type in Python?

It is useful to have the interpreter derive the type of a variable automatically. This on its own is similar to the auto keyword in C++11. However, in Python variables can change their type after ...
0
votes
1answer
72 views

Should instance variables be bound to the instance right in the beginning of the method they are created in?

A common problem for me - and it's not really a problem, but somehow I again and again ask myself, what is the normal way to handle this - is that there is a method and within this method a couple of ...
0
votes
1answer
94 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
votes
2answers
147 views

php make dollar optional [closed]

Is there any reason the PHP language could not be updated in a future version to make the $ prefix on variable names optional? Reasons that would break existing code? I'm thinking it would still be ...
4
votes
6answers
2k views

Should I store x,y coordinates as an array, a class object, or two variables?

I have a MyObject which has an x and y coordinate. as far as I can see, I can store it in three ways: class MyObject: def __init__(self, x, y): self.x = x self.y = y class ...
1
vote
2answers
172 views

Should I sacrifice code succintness to ensure the narrowest variable scope? [duplicate]

In many languages (e.g. both Perl and Java - which are the two languages I work most with) it is possible to narrow the scope of local variables by declaring them within a block. Although it adds ...
0
votes
5answers
640 views

Representation of a question mark in variable names [closed]

I once in my childhood read a SF story in which it was assumed that the capital letter 'P' would be a good representation for a question mark, if you cannot use that character directly, eg. in ...
5
votes
2answers
957 views

Why to declare a String (as final) and then use it?

In a typical spring mvc validator class, while inserting an errorCode value in the Errors object, what difference does it make between using a String (props.somefield.req) like so ...
1
vote
4answers
1k views

Best datatype to store a ternary, or three-state variable

Disclaimer: I know that datatypes are a little bit subjective to which scripting/programming language you are using, I like to write in Python as a matter of preference; though I am happy to hear ...
2
votes
1answer
1k views

Where should variables be declared [duplicate]

Considering I have a for loop in a method of a class. Should the incremented variable be declared as member of the class, or should it be declared in the method it uses it(or even in the for loop, ...
0
votes
3answers
1k views

Isolating unit tests in python

As a 30-year software developer, mostly in OO languages, but a newbie at python, I'm looking to find what is best practise for isolating unit tests in python. Let's say I have the following, ...
1
vote
2answers
1k views

What is the underlying mechanism behind va_list and where is it defined?

http://www.cplusplus.com/reference/cstdarg/va_list/ According to the above link, va_list is an argument or parameter used in some macros - va_start, va_arg, va_end. These macros are present in the ...
6
votes
5answers
566 views

Using π, φ, λ etc. as variable names while programming? [duplicate]

This is a function in the d3.v3.js file (the graph library D3.js): function d3_geo_areaRingStart() { var λ00, φ00, λ0, cosφ0, sinφ0; d3_geo_area.point = function(λ, φ) { ...
2
votes
1answer
61 views

When should I pass setting-like value as class' variable and when as an assoc. array?

Following my other question, is there a general rule of thumb, when we should pass a setting-like value, that controls class' behavior (for example displayed texts) as as class' constant or variable, ...
1
vote
1answer
120 views

When should I pass value as class variable and when as a method argument?

Is there a general rule of thumb, when we should pass a value as as class variable and when as a method argument? Or is it just a choice of the developer? For example -- are there any reasons, why ...
1
vote
2answers
178 views

Scope vs Visiblity vs Lifetime vs Accessibility vs etc

I have been trying to understand what it means to say "scope of a named entity". In reading about scope, there are terms like visibility, lifetime, accessibility and more that are used. What is ...
2
votes
2answers
357 views

Is there a difference between declaring variables outside or inside a loop? [closed]

Is there any difference if I were to write something like this: int row,col; for(row = 0; row < data.length; row++){ for(col = 0; col < data[row].length;col++){ //do ...