What is difference between read-only and const

Question

Accepted Answer

Read-only is a runtime concept while const is a compile-time concept.

Read-only variables can be assigned a value only once during runtime.
Const variables are initialized at compile-time and cannot be modified during runtime.
Read-only variables can be assigned a value in the constructor of a class.
Const variables can be used to define constant values like pi or e.
Read-only variables are declared using the 'readonly' keyword.
Const variables are declared using the 'const' keyword.

Accepted Answer

Read-only" and "const" are terms used in programming to indicate that a value or variable cannot be changed. However, their usage can vary depending on the programming language.

In many languages like JavaScript, "const" is used to declare variables that cannot be reassigned after they are initially given a value. This means the variable itself can't be changed to point to a different value. However, if the value is an object or an array, the properties or elements of the object/array can still be modified.

"Read-only" is a broader term and often implies that not only the variable cannot be reassigned, but also the value it holds cannot be changed in any way. It's more restrictive than "const".

In languages like C++, "const" can be used to declare constants and indicate that a variable cannot be modified. On the other hand, "read-only" might be used to describe a more complex concept involving access control, indicating that certain parts of a program can only "read" a value and not modify it.

The precise meaning of these terms can vary between programming languages, so it's always important to refer to the documentation of the specific language you're usi

ng.

What is difference between read-only and const

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