What are common variable declaration errors in JavaScript?

What are common variable declaration errors in JavaScript?

Common errors include using undeclared variables, incorrect use of 'let' and 'const', and syntax errors.

Can you give me an example of an undeclared variable error?

Sure! If you try to use a variable without declaring it first, like console.log(x); where x is not defined, it will throw a ReferenceError.

What about using 'let' and 'const'? What mistakes can happen?

Using 'let' or 'const' in the wrong scope can lead to errors. For example, declaring a variable inside a block and trying to access it outside will result in a ReferenceError.

How can I avoid these errors in my code?

To avoid these errors, always declare your variables with 'let', 'const', or 'var', and be mindful of their scope.