That’s it for today, if you have any thoughts, suggestions, feedback, or anything else, feel free to hit me up at twitter. I promise you, it will make your life so much easier. So next time you will face a strange type error, try to abstract away from what your code does and try to look at it from the perspective of the compiler.
currentValue - The current element being passed from the array. It is initialValue for the first call if supplied. It takes in: accumulator - It accumulates the callbacks return values. callback - The function to execute on each array element. ConclusionĪlthough we’ve covered only 1 possible case with reduce, all of the errors that you will face usually come for the same reason.Īlso, the thinking process that we’ve used to understand the error is very helpful to debug any type error that you’ll face. The reduceRight() method can take two parameters. Quick tip: If you see a big type error, scroll to the bottom and check few last lines, they usually contain the most useful information. Of course, I showed you a very simple case where it’d be very difficult to make a mistake, but in the real project when you have way more code, it’s simple to forget about such small details. Let’s keep this in the back of our mind before proceeding. Type 'number' is not assignable to type 'string'.Īlthough in this particular case error may seem a bit confusing, it’s better to have any error than to end up with buggy code. map(), filter()and reduce() methods are invoked on arrays and written in Array class in JavaScript.
