An array is a systematic arrangement of similar objects, usually in rows and columns.

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42
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2answers
5k views

How do I move away from the “for-loop” school of thought?

This is a rather conceptual question, but I was hoping I could get some good advice on this. A lot of the programming I do is with (NumPy) arrays; I often have to match items in two or more arrays ...
30
votes
6answers
134k views

Is initializing a char[] with a string literal bad practice?

I was reading a thread titled "strlen vs sizeof" on CodeGuru, and one of the replies states that "it's anyways [sic] bad practice to initialie [sic] a char array with a string literal." Is this ...
29
votes
11answers
9k views

How does the “Fourth Dimension” work with arrays?

Abstract: So, as I understand it (although I have a very limited understanding), there are three dimensions that we (usually) work with physically: The 1st would be represented by a line. The 2nd ...
21
votes
5answers
7k views

What's the use of .Any() in a C# List<>?

I've been discussing this with colleagues, and we couldn't figure out what the use is of .Any for any given List<>, in C#. You can check the validity of an element in the array like the ...
14
votes
2answers
34k views

Should I use a list or an array?

I'm working on a windows form to calculate UPC for item numbers. I successfully create one that will handle one item number/UPC at a time, now I want to expand and do it for multiple item ...
13
votes
1answer
434 views

Why using sizeof of type to calculate the number of elements in an array is considered inferior to using sizeof of an element?

I'm reading "King K.N's C programming" and I'm reading the following statement: We discussed using the expression sizeof(a)/sizeof(a[0]) to calculate the number of elements in an array. The ...
10
votes
1answer
2k views

PHP: when to use arrays, and when to use objects for mostly-data-storing code constructs?

PHP is a mixed paradigm language, allowing to use and return non-object data types, such as arrays. I pose a question to try to clarify some guidelines for selection of arrays vs objects when deciding ...
9
votes
8answers
23k views

What is the difference between an Array and a Stack?

According to Wikipedia, a stack: is a last in, first out (LIFO) abstract data type and linear data structure. While an array: is a data structure consisting of a collection of elements ...
8
votes
3answers
4k views

Ordered enumeration: IEnumerable or Array (in C#)?

Typical context: I make an extension method for a collection which considers that the elements are ordered. The function starts at the beginning, at index 0, and the order has significance. Examples: ...
7
votes
4answers
2k views

Why can't C arrays have 0 length?

The C11 standard says the arrays, both sized and variable length "shall have a value greater than zero." What is the justification for not allowing a length of 0? Especially for variable length ...
6
votes
6answers
1k views

why are both index[array] and array[index] valid in C?

For example consider: int index = 3; int array[4] = {0, 1, 2, 3}; then both index[array] and array[index] are valid expressions, much like *(index + array) and *(array + index). In C arrays why is ...
6
votes
2answers
2k views

How to remove the boundary effects arising due to zero padding in scipy/numpy fft?

I have made a python code to smoothen a given signal using the Weierstrass transform, which is basically the convolution of a normalised gaussian with a signal. The code is as follows: #Importing ...
5
votes
2answers
163 views

How to store ordered information in a Relational Database

I am trying to understand how to properly store ordered information in a relational database. An example: Say I have a Playlist, consisting of Songs. Inside my Relational Database, I have a table of ...
5
votes
4answers
1k views

Why do arrays in Java not override equals()?

I was working with a HashSet the other day, which has this written in the spec: [add()] adds the specified element e to this set if this set contains no element e2 such that (e==null ? e2==null : ...
5
votes
1answer
177 views

At ping, why do we have to do array copying instead of passing on the source array that the client sent to us?

So I have been googling about this OpenSSL heart-bleed thing and somehow sees that it is caused by the heartbeat extension which requires client to ping the server to show its aliveness and it all ...
5
votes
2answers
391 views

Which design pattern is illustrated by inheriting IStructuralComparable interface?

We know that some design patterns are found so useful that they become features of the language itself. For instance, the interface IEnumerator which is implemented by Array object. This helps in ...
5
votes
2answers
1k views

Implementing non-fixed length array support in a compiler

I'm thinking of building a language for PIC microcontrollers. I want to be able to use non-fixed size arrays, like this: Declare the variable as int[] Wait for input from serial connection Make the ...
5
votes
3answers
405 views

Generating Deep Arrays: Shallow to Deep, Deep to Shallow or Bad idea?

I'm working on an array structure that will be used as the data source for a report template in a web app. The data comes from relatively complex SQL queries that return one or many rows as one ...
4
votes
5answers
575 views

What's the effect of this assignment (whatever the language)?

I think my book (Programming Languages: Principles and Paradigms) is wrong. a is a vector, assume a C-like language: b = 0; a[f(3)] = a[f(3)] + 1; int f(int n) { if(b == 0) { b = 1; ...
4
votes
3answers
1k views

Lisp: Benefits of lists as code over arrays as code?

Question for lisp programmers: Lisp code is lisp data, usually lists. Is there an advantage to code being lists over code being arrays? Would macros be easier to write/faster to run? You can ...
4
votes
3answers
4k views

C Flexible Arrays: When did they become part of the standard?

I learned to program in C many years ago, and used C steadily for about 10 years. These days, I occasionally have to look at C code, because our Informix 4GL RDS customized runners also contain C ...
4
votes
5answers
6k views

Retrieving maximum value from a range in unsorted array

I have an unsorted array. I have queries in which I give a range and then the maximum value from that range has to returned. For example: array[]={23,17,9,45,78,2,4,6,90,1}; query(both inclusive): 2 ...
4
votes
3answers
543 views

@SuppressWarnings in generic array declaration

While doing a coding test, I ran into a problem where I need to initialize an array of generic type in Java. While trying to figure out how to do that, I looked at this Stack Overflow question and it ...
4
votes
2answers
3k views

Array Multiplication and Division

I came across a question that (eventually) landed me wondering about array arithmetic. I'm thinking specifically in Ruby, but I think the concepts are language independent. So, addition and ...
4
votes
1answer
321 views

Why is Array.prototype designed to be a fully functional array?

In the below visualisation, There are two array objects(cars & bikes) that are created with below syntax, var cars = new Array("Saab", "Volvo", "BMW"); var bikes = ["Honda", "Yamaha"]; whose ...
3
votes
6answers
1k views

Why isn't the line count in Visual Studio zero-based? [closed]

This just struck me as an oversight by Microsoft. Since arrays and other data-structures within the .NET framework begin from zero (zero-based) why don't we have a line 0 within the code view in ...
3
votes
3answers
751 views

Is there a way to add unique items to an array without doing a ton of comparisons?

Please bare with me, I want this to be as language agnostic as possible becuase of the languages I am working with (One of which is a language called PowerOn). However, most languanges support for ...
3
votes
3answers
3k views

Specific reasons to create own array class over using std::array?

What specific conditions or requirements should you create your own array over using std::array? Here is my background: I'm developing a small simple library that a small group of people will use ...
3
votes
5answers
313 views

What defines the dimensionality of an array?

I know that when we speak about an array having 1, 2, or 4 dimensions, we mean arrays like this: 1: [0] 2: [0,0] 3: [0,0,0] 4: [0,0,0,0] ... Is the first 'axis' of an array the only thing that ...
3
votes
3answers
2k views

Best way to choose random element from weighted list

I want to create a simple game. Every so often, a power up should appear. Right now the different kinds of power ups are stored in an array. However, not every power up should appear equally often: ...
3
votes
2answers
838 views

Should the 12-String be in its own class and why?

This question is regarding a homework project in my first Java programming class (online program). The assignment is to create a "stringed instrument" class using (among other things) an array of ...
3
votes
2answers
2k views

CA1819: Properties should not return arrays. Does this happen only with arrays? If yes, why?

I have a question about CA1819 msdn performance warning. The rule is: Arrays returned by properties are not write-protected, even if the property is read-only. To keep the array tamper-proof, the ...
3
votes
1answer
900 views

The array class in C# - Implementation questions

I am studying the Array class in C#. The following is the implementation of System.Array class: [SerializableAttribute] [ComVisibleAttribute(true)] public abstract class Array : ICloneable, IList, ...
3
votes
3answers
493 views

How do you iterate through an array and delete an element?

I have an array and I can iterate through it. I know that it is impossible to change the size of an array; however, how do I take out a certain element that I not want in the array anymore? Example: ...
3
votes
1answer
644 views

sort multidimensional array recursively - is this reasonable

In a nutshell, I needed to traverse any number of dimensions of a multidimensional array (or not) and I wanted the process to be as predictable as possible (in order to proliferate the pattern ...
3
votes
2answers
96 views

Reducing a sequence of array modification operations (insert, sort, replace, remove)

Given a plain array of values, e.g. ["Apple", "Orange", "Banana", "Strawberry"] and a list of operations from the set of [insert, delete, sort and replace], e.g. [ {cmd: "insert", index: 2, ...
3
votes
1answer
426 views

Why is iterating through List<T> more expensive than iterating through Array in .NET?

According to the answers in this post, List<T> is backed by an Array. According to this article, list iteration is considerably slower than array iteration. If Lists are arrays 'under the ...
3
votes
2answers
733 views

Data structure for grid with negative indeces

Sorry if this is an insultingly obvious concept, but it's something I haven't done before and I've been unable to find any material discussing the best way to approach it. I'm wondering what's the ...
3
votes
3answers
2k views

Arrays vs Objects in view template

I am wondering, in view templates, what would contribute to me choosing between using arrays or objects for getting things printed out in arrays {{$user->zip_code}} vs {{$user['zip_code']}} I'm ...
3
votes
2answers
178 views

What would be the optimal way to solve a problem like this?

I have a problem where I have to change all the Xs in a 2D array into 0s, and I have to calculate the minimum steps (where a single step consists of changing an entire row or column) required to do ...
3
votes
2answers
426 views

How to draw rectangles for 2D arrays

I have an 2D boolean array that looks like this: [0][0][0][0][0][0][0][0][0][0] [0][0][0][0][0][0][0][0][0][0] [0][0][0][0][0][0][0][0][0][0] [0][0][0][1][1][1][0][0][0][0] ...
3
votes
1answer
147 views

Conveniently sorting and (binary?) searching an array of pairs of numbers?

So I have an array of distinct pairs of positive integers. That is, my array looks something like this (for instance): { (1,5) , (6,4), (5,3), (2,3), (2,4) } And my task is, for a given pair (a,b) ...
2
votes
6answers
2k views

Settle an Argument: String vs. Array?

True or False: A string is the same thing as an array. I had an interview the other day and the above question was asked. I said false, but the interviewer said it was actually true. I explained to ...
2
votes
3answers
703 views

What are pros and cons of using temporary “references”?

In C and C++ (and I guess other languages that allow taking a "reference" to an array element or something similar), when you have an array like type, accessing individual elements of such an array ...
2
votes
3answers
300 views

Is it a good idea to modify the array keys in foreach

Some times I need to modify an array key for example something like: $temp = array(); foreach($arrayIWantToModify as $key => $value) { if($value % 2) == 0) { $temp['odd_' . $key] = ...
2
votes
1answer
327 views

Beginners C# question about Array.Reverse

I am sitting through a very well-explained and thorough video tutorial series, using Visual Studio 2012 as my developing environment. Anyway, one thing that is hard to figure out is this. Say you ...
2
votes
3answers
289 views

What language has integrated “list insertion” as part of code *syntax*?

Many programming languages permit natural manipulation of strings, and some languages permit the manipulations of lists too. More often then not (always?), these operations are done as procedure ...
2
votes
4answers
3k views

How do you find the first common element in two arrays

How do you find the first common element in two arrays? My attempt: I looped through each at the same time and add the current value to a separate set for each of the lists. Also, check if the ...
2
votes
2answers
147 views

How to create a 2D array at runtime in Ada? [closed]

In Ada programming, What is a best practice way to create a 2D array of a size that is specified by the user? I'm teaching myself Ada for work (after many years of C programming), and I'm having ...
2
votes
1answer
322 views

Why does Java support brackets behind variables and even behind method signatures? [closed]

Java allows this: class X{ int i,j[]; // j is an array, i is not } and even worse, it allows this: class X{ int foo(String bar)[][][] // foo actually returns int[][][] { return null; } ...