How do you declare a variable in JavaScript?

In JavaScript, variables are used to store data values that can be accessed and manipulated throughout your code. Declaring a variable involves specifying the variable name and optionally assigning an initial value to it.

1. In JavaScript, variables are declared using the var, let, or const keywords.
2. The var keyword declares a variable with function scope or global scope.
3. The let keyword declares a variable with block scope, allowing for more localized variable usage.
4. The const keyword declares a constant variable, which cannot be reassigned after initialization.
5. It is possible to declare a variable without assigning an initial value. In such cases, the variable will have the value undefined.
6. To assign an initial value to a variable, use the assignment operator (=) after the variable name.
7. The value assigned to a variable can be of any data type, such as numbers, strings, booleans, objects, or arrays.
8. It is good practice to declare variables at the top of their respective scope to avoid potential hoisting and scoping issues.