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Questions tagged [casting]

Casting is a process where an object type is explicitly converted into another type if the conversion is allowed. This process might lead to a change in value.

Some algorithms have significant performance differences for different data-types, for example, calculating the N-dimensional median is much is much faster for integers than float type data. Therefore, the use of casting can be important for code performance.

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How to cast int to enum in C++?

How do I cast an int to an enum in C++? For example: enum Test { A, B }; int a = 1; How do I convert a to type Test::A?
user1509260
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Shorter syntax for casting from a List to a List?

I know it's possible to cast a list of items from one type to another (given that your object has a public static explicit operator method to do the casting) one at a time as follows: List ListOfY = new List(); foreach(X x in ListOfX) …
Jimbo
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What is the difference between static_cast<> and C style casting?

Is there any reason to prefer static_cast<> over C style casting? Are they equivalent? Is there any sort of speed difference?
dicroce
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Casting a number to a string in TypeScript

Which is the the best way (if there is one) to cast from number to string in Typescript? var page_number:number = 3; window.location.hash = page_number; In this case the compiler throws the error: Type 'number' is not assignable to type…
Ma Jerez
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How to cast an Object to an int

How can I cast an Object to an int in java?
Sheehan Alam
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Fastest way to convert string to integer in PHP

Using PHP, what's the fastest way to convert a string like this: "123" to an integer? Why is that particular method the fastest? What happens if it gets unexpected input, such as "hello" or an array?
nickf
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How do I convert from int to Long in Java?

I keep finding both on here and Google people having troubles going from long to int and not the other way around. Yet I'm sure I'm not the only one that has run into this scenario before going from int to Long. The only other answers I've found…
Ghosty
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Haskell: Converting Int to String

I know you can convert a String to an number with read: Prelude> read "3" :: Int 3 Prelude> read "3" :: Double 3.0 But how do you grab the String representation of an Int value?
Squirrelsama
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SQL: Subtracting 1 day from a timestamp date

I am using Datagrip for Postgresql. I have a table with a date field in timestamp format (ex: 2016-11-01 00:00:00). I want to be able to: apply a mathematical operator to subtract 1 day filter it based on a time window of today-130 days display…
J-Ko
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TypeScript enum to object array

I have an enum defined this way: export enum GoalProgressMeasurements { Percentage = 1, Numeric_Target = 2, Completed_Tasks = 3, Average_Milestone_Progress = 4, Not_Measured = 5 } However, I'd like it to be represented as an…
AnimaSola
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Convert Float to Int in Swift

I want to convert a Float to an Int in Swift. Basic casting like this does not work because these types are not primitives, unlike floats and ints in Objective-C var float: Float = 2.2 var integer: Int = float as Float But this produces the…
kev
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Change type of varchar field to integer: "cannot be cast automatically to type integer"

I have a small table and a certain field contains the type "character varying". I'm trying to change it to "Integer" but it gives an error that casting is not possible. Is there a way around this or should I just create another table and bring the…
itsols
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String was not recognized as a valid DateTime " format dd/MM/yyyy"

I am trying to convert my string formatted value to date type with format dd/MM/yyyy. this.Text="22/11/2009"; DateTime date = DateTime.Parse(this.Text); What is the problem ? It has a second override which asks for IFormatProvider. What is this?…
Shantanu Gupta
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Implicit type conversion rules in C++ operators

I want to be better about knowing when I should cast. What are the implicit type conversion rules in C++ when adding, multiplying, etc. For example, int + float = ? int * float = ? float * int = ? int / float = ? float / int = ? int / int = ? int ^…
Matt Montag
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Downcasting in Java

Upcasting is allowed in Java, however downcasting gives a compile error. The compile error can be removed by adding a cast but would anyway break at the runtime. In this case why Java allows downcasting if it cannot be executed at the runtime? Is…
Warrior
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