I would like to declare a type-enforced array of items and be able to derive a union type from it. This pattern works if you do not explicitly give a type to the items in the array. I am not sure how to best explain it so here is an example: EXAMPLE 1 EXAMPLE 2 Here is an example of
Tag: typeof
How to detect if a variable is a pure javascript object
I have a function I need to pass an object to. I use typeof operator to make a check before processing. But looking at this link, it appears that many javascript instances, such as array or regex, are typed as Objects. I need my argument to be a pure object (like this : {key: value, . . .}). Is their
How to efficiently check if variable is Array or Object (in NodeJS & V8)?
Is there any way to efficiently check if the variable is Object or Array, in NodeJS & V8? I’m writing a Model for MongoDB and NodeJS, and to traverse the object tree I need to know if the object is simple (Number, String, …) or composite (Hash, Array). It seems that V8 has fast built-in Array.isArray, but how to check
When iterating over values, why does typeof(value) return “string” when value is a number? JavaScript
I’m using Google Chrome for this test: Contrary to intuition, the first loop alerts “string” three times, while the second loop alerts “number” three times. I was expecting both loops to alert “number” three times. How is the first loop implemented in JavaScript? In other words, if the for-each is syntactic sugar, what is its equivalent using a standard loop?