Hey guys 👋🏻,
In this article, we will understand
✔ What are Closures ?
✔ Code Example with explanation.
What are Closures ?
This means that it registers the outer lexical environment and the variables present in there and it remembers the values of these variables.
=> This also means that the reference that gets setup enables the code inside the inner function to see variables declared outside the inner function, regardless of when and where the function was called.
So let us see an example,
In the above code, we have a
calculateSimpleInterest function that takes on a
principal value inside which we have function
useRateAndTime that takes on
time and computes the simple interest for us. At the bottom of the
calculateSimpleInterest function, we return the
So for our
useRateAndTime forms a closure with the lexical environment of the execution context which gets created when
calculateSimpleInterest function is invoked, closing over the variables defined inside the outer function (if any).
Let us see the usage
With the invocation of
calculateSimpleInterest function using a value of 10000 as
principal, a new function
useRateAndTime gets created and in it the value of
principal gets locked and is returned. Now we have the
useRateAndTimeFn constant in which we have the returned function having the
principal locked in. So we call the inner function now by passing the value of
time. Lastly we store the returned value in a variable with the name of
✔ Use closures if you want a function to always have access to a private piece of state.
So this is it for this article. Thanks for reading.
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