Questions tagged [data-types]
The data-types tag has no usage guidance.
144
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Parsing complex data type names
How do compilers parse complex data types names like function pointers. The type has to be somehow put into the AST or it has to be processed during parsing. What are the pros and cons of different ...
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Integer type for data structure index
I have implemented an append-only tree data structure as a class in C++20. Internally it uses std::vector<Node<T>> where Node<T> contains an int parent_index and T payload. A node ...
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Time limit or built-in flush of HashTable entries
Is there a standard data type which is a struct or a table or a dictionary which will always delete objects that are older than t minutes? for example if I want to make sessions expire after 60 ...
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117
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What is the purpose of types which may be replaced by others?
In Kotlin or Java we have many different types: integer, byte, double, long, float, string, character, etc.
But one can use an integer instead of byte, and a double instead of an integer.
Why we need ...
user390675
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What is the viability of engineering an integral type with values ranging from -1 to 254? Do types like this even exist?
In software engineering, often developers will utilize three different states of a signed integer, as a trilean:
This tends to be quite typical:
-1 - Represents something akin to a null pointer, as in ...
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Should all structures be ADTs?
Is there any specific category an ADT must be in? I'm struggling to find out how best to represent objects in the program for example:
As a record:
struct Person {
int age
};
Or as an ADT:
struct ...
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Do any programming languages use types as values? Would there be any point?
The standard way that types are handled in programming languages that have such a concept, is that they are:
removed entirely at compile time and are just used to determine memory layout, function ...
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What is the Difference Between Float and Double Data Types? [duplicate]
Apart from the memory size of both data types, I want to know any other differences and also want to know when we use float and when we use double?
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3
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155
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Is it called "composition" if we are using primitive data types?
The following is an example of "composition":
public class Car
{
Engine engine; // Engine is a class
}
But is it still called "composition" if we are using primitive data ...
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40
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Is there a simpler way to monitor changes to a piece of data, and disallow removing the data from monitoring?
I'm working on an algorithm visualizer for sorting algorithms. Give it a (user-submitted) sorting algorithm, hit run, it'll generate a random list of integers and show you what the algorithm looks ...
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152
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Why do some languages decouple operations from data type?
This is a pretty difficult question to frame. But I'll try my best.
In some languages, data types are decoupled from the operations they can perform, while in other languages like JavaScript they are ...
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Is there a difference between abstract data type and interface?
From what I understand, an abstract data type is basically some data and what we are allowed to do with that data (ex. a list with a set of data and an attribute size and the functions get(), set(), ...
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484
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Why am I getting complex errors even with simple C++ code?
I started to play with C++ recently. One of the difficulties I have quite often is when the compiler tells that there is an issue with the types: more often than not, those compiler errors look ...
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381
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How to visualize a Stream object (and some other data types)?
I want to make a small programming tutorial which will have a number of images visualizing various data types, but I am not sure how to draw these images of the data types.
Assume that I have a ...
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What goes into a computer deciding how many memory locations to assign for specific data types in C?
I have learned file memory management and some very simple CPU assembly for manual memory manipulation. Still, I feel like there is a gap in my knowledge when it comes to modern, complex computers, ...
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Is there a name for this pattern of composing a type safe return type from different levels of nested related entities?
I have a problem in my app where I have many entities that can all reference each other in different ways. For example, I have a Job (e.g. build house) that I might assign to a team called "Plumbers" ...
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103
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A size-type vs index-type conundrum
Suppose I'm writing C or C++ code which deals with... ok, let's make it citizens in a state. In this state, citizens have numeric id's (not strings - numbers); and for reasons of performance, or ...
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How do B-Trees used in databases sort data based on different fields?
I know majority of databases uses B-Trees, and I can see how using a balanced binary tree will give fast sort times, for ordering by ID or whatever else the primary key is; but how are databases able ...
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154
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How do Haskell Lists Desugar?
So, I was wondering about how Haskell's lists are implemented. I looked it up, and found this:
data [] a = [] | a : [a]
So I get that you can write lists like this if you want to:
a:b:c:[] -- ...
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What is the correct way to dynamically declare the type of a variable (in Java)? [closed]
Disclaimer: I previously posted this on Stack Overflow, but it seems that perhaps that was not the correct site for the question. If this is still not the correct site, please let me know.
I'm ...
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why aren't the platform specific integer types in C and C++ (short, int, long) deprecated?
TL;DR: Why isn't everybody screaming, "Don't use short, int, and long unless you really need to, and you very likely don't need to!"
I understand that, in theory, by using the types short, int, and ...
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Data Types Based Database
I was wandering if there exists some kind of database that organises data based on some declared type rather than tables or collections.
I'll try to explain better with an example.
Let's say I have ...
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244
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When is it a good idea to include explicit type declarations in Kotlin?
In Kotlin, specifying the return types of functions and the types of variables is usually optional but can be optionally included.
I've encountered a few benefits of including them:
It sometimes ...
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Using Null/None/Nil vs empty data types
This question is more coding style related which is why this question is asked here.
I'm new to Python, coming from PHP. I've been looking through Python style guides & code examples, I've ...
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486
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Language design : How to type higher order functions parameters?
I'm trying to design a theoretical programming language and I'm facing a problem with high order functions.
The language is strong-typed, so the way to define a standard function is like so :
...
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2
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481
views
What are the "scalar fields" and "composite fields" in JAVA?
Need to understand the below definition, from the protobuf tutorial:
mergeFrom(Message other): (builder only) merges the contents of other into this message, overwriting singular scalar fields, ...
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530
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Can int16_t be easier on the processor then int?
I know that the compiler and architecture of a processor also have a role to play in this. But this is more of a "can it" rather then a "does it" question.
I have already tried to research this, but ...
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242
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What to do with data types with lots of connections in a UML class diagram
I have a Pose data type, consisting of x, y, and rotation values.
This being a robotics application, the Pose data type is used in about a dozen places throughout the application. Connecting all ...
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Convert between enum and discriminated union
Is there a software pattern (or some recommended guidelines) for how to convert between enum values and discriminated unions? Or more specifically: project a discriminated union onto its enum case? ...
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147
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Not understanding ADT concept from book "Object-oriented software construction 2/e"
I've been learning object-oriented concept from this book, and stuck in a specified concept in the middle of chapter 6.
No one could understand my question without brief prologue, so I'm starting with ...
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How float data type stores number greater than 2^23? As Mantissa is only 23 bits
Can someone explain how floating point numbers are stored in C, as for 32-bit float, 1 bit is parity, 23 bits for mantissa and 8 bits for exponent. So for numbers greater than 2^23(still in the float ...
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117
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What is the term for the side on which a variable type is written in a given language?
In the case that a type is specified, it could be on the left (before) or the right (after) of the variable name.
For example, C, C# and Java have the type specified before the variable:
int num = 5;...
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How the value of the integer variable is stored in a memory by bytes/bits?
In C program I'm doing below stuff
int x = 4;
Let us assume integer has 2 bytes in this case.
So my question here is
the variable x will hold two bytes that mean 16 bits. So here how the value 4 ...
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How do variables in C++ store their type?
If I define a variable of a certain type (which, as far as I know, just allocates data for the content of the variable), how does it keep track of which type of variable it is?
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How to store external numeric IDs - as strings or as integers?
Every now and then we programmers need to communicate with external systems (not under our own control). It's frequent that in such cases we need to keep track of some sort of identifiers that these ...
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Differentiating Between ASCII and Unicode in File Spec
I am developing against a file spec that lists the data type for certain fields as
CHAR(<length>)
The spec is for a fixed width flat file. In most cases, possible values to populate the fields ...
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How should I store "unknown" and "missing" values in a variable, while still retaining the difference between "unknown" and "missing"?
Consider this an "academic" question. I have been wondering about about avoiding NULLs from time to time and this is an example where I can't come up with a satisfactory solution.
Let's assume I ...
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Does primitive obsession apply to columns of tables in database?
For example, in a Student object, in order to avoid primitive obsession, I should change
public class Student{
public String name;
public int age;
}
into
public class Student{
public ...
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Subclassing numeric types for safety
I'm writing something that handles length units, say, metres and feet. I don't want to accidentally convert between them (trying to avoid something like the Mars Climate Orbiter crash).
I'd like to ...
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Only one number type in language design
I am currently learning about compiler construction and language design and I am thinking about what native datatypes I want to support in my language. Now there is a whole lot of languages that make ...
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Not sure how to setup my data for a waypoint system
I have a system i've written on paper and am trying to write this into C# in a easy to use manner.
I want a series of connected waypoints (where by waypoints can be connected to any number of other ...
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Is there a practical benefit to using the smallest datatype possible?
In C# (and other languages), we can define a numerical variable as a short, an int, or a long (among other types), mostly depending on how big we expect the numbers to get. Many mathematical ...
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React JS: Mixing data types for one state property
In the spirit of minimising state I always have a desire to mix data types for a given state property. For instance, if I were creating a React page that rendered a list of items that could either be ...
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When writing a Qt application is good practice to ALWAYS prefer Qt function implementations, data types, and classes when they are available?
I'm just starting out with Qt and I really want to try and keep my application as separated from Qt as possible in case I decide to use a different toolset later, but at the same time don't want to ...
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Built-in type AND value checking of parameters?
Does any programming language have a concept of checking the type and value of a given parameter without adding an explicit if (myParam < 0) { .. } within the function?
A pseudocode example:
...
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Which layer for custom type (DDD)
If I have a custom type (or maybe an enum) like for ex. a Range:
Public Class Range
Sub New(minimum As Single, maximum As Single)
Me.Minimum = minimum
Me.Maximum = maximum
...
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Why are Python sets and dictionaries not ordered by default?
I understand the difference between ordered and unordered sets, and I understand why for many purposes, we don't need ordered sets. But all set operations are still possible on ordered sets, and sets ...
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Which is a more efficient way of storing data in a database using Objects or strings (Database design)
Which method is better to store the data in a database and why?
Here is a restaurant example. I'm using a SQL database and JSON to communicate with the database.
Imagine each row is a column in a ...
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Are C++ types classes? [closed]
I am trying to understand if C++ types are classes, like in Python for example.
Otherwise what datatype is the type itself? E.g. int a = 10 what is int? Is just a token label used by the compiler to ...
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About my database date datatype crusade: Valid? Worthwhile? Does anyone else feel it?
I spend a lot of time answering SQL questions over on SO. I frequently come across queries of this ilk:
SELECT * FROM person WHERE birthdate BETWEEN '01/01/2017' AND '01/03/2017'
SELECT * FROM ...
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