In JavaScript, a closure is a feature where an inner function has access to variables from an outer function even after the outer function has finished executing. This happens because the inner function ‘remembers’ the environment in which it was created.
Here’s a simple way to understand it:
- Outer Function: You have an outer function that defines some variables.
- Inner Function: Inside this outer function, you create an inner function. This inner function can use the variables defined in the outer function.
- Closure: Even after the outer function has finished executing and its scope is gone, the inner function still has access to those variables. This persistent access to the variables of the outer function is what we call a closure.
It’s like having a backpack. When you leave your house (the outer function), you take things (variables) with you in your backpack. Throughout the day (even after you’ve left your house), you can still use everything you put in your backpack. That backpack and its contents are your closure in the outside world.
