What is a Constant in C#?

In the Context of C#, a regular is a type of discipline or neighborhood Variable whose price is about at Compile time and might by no means be cHanged at Run Time. It is similar to a variable by way of having a name, a fee, and a reminiscence region. However, it differs from the variable by its feature of getting iNitialized most effective as soon as in the utility. A regular is said the use of the Keyword "Const".

Variables of built-in type, with the Exception of SySTEM.Object whose non-converting cost is understood at collect time, can be declared as constants. During compilation, the constant cost is substituted for its literal fee into the Intermediate Language Code by using the Compiler. This consequences in higher Integrity of the utility via decreasing unintentional insects. Usage of constants also improves perFormance over ordinary variables. It improves code clarity and provides better upkeep, considering that it's miles simpler to replace the steady price in a unmarried place before recompilation of Software.

What Does Constant Mean?

A steady has the subsequent traits or have to adhere to the subsequent policies:

• One or more constants of a given type may be declared in a unmarried Declaration.
• A regular may be of any kind, along with an sbyte, byte, quick, ushort, int, uint, long, ulong, char, flow, double, Decimal, bool, String, Enum-type, or reference kind.
• A sort of a regular ought to be at least as available because the constant itself.
• A regular can depend upon other constants if dependencies are not of a circular nature.
• A constant can't be used for a way, belongings, or Event.
• A consistent can not be of person-described sorts, inclusive of magNiFicence, struct, and Array.
• While declaring a steady, a Static modifier can't be used.
• Assigning an already assigned steady variable at runtime effects in a compilation error.
• As no cope with is associated with a constant at runtime, it cannot be exceeded by means of reference and can't seem as an l-price in an Expression.
• A constant may be used with get admission to modifiers along with Public, Private, blanketed, inner, or included Internal.
• Constant declarations made on the Class degree are saved in assembly Metadata.

Some of the Great practices while using constants consist of:

• Constants need to be initialized at some point of declaration.
• Constants are to be used with meaningful names as they constitute unique values.
• To outline more than one non-fundamental/crucial constants, a single static magnificence (containing steady member variables) can be used to group them.
• The scope of the constant variable is confined to a single meeting, elegance, or Method. Hence, whilst referring constant values described in different assemblies, it needs to be recompiled for any change earlier than compiling the based meeting.

A steady differs from the readonly variable in that the previous needs to be initialized throughout declaration time and is static, whilst the latter can be initialized throughout announcement or anybody time (like in a Constructor for you to have distinct values primarily based on the constructor kind). Hence, a constant is known as a collect-time steady, and a readonly variable is a runtime steady.