To do this we could apply the map operator, providing a function that returns an object with just these properties:
So what are some other common scenarios where we could put the map method to use? Using Array.map, we may also want to transform objects. For instance, suppose we have an array of objects with a first and last name property and we want to tack on a full name property to each object.
Similar to our array example with objects, we may also want to transform an observable of objects with the map operator. For instance, suppose we have an observable of click events that we wish to transform into an observable of objects containing just the clientX and clientY coordinates of these events.
Or maybe you need to extract a value from a stream read more of input events to perform a calculation or initiate a request. Or perhaps you just want to extract a single property from an object, like a key code, to perform another action down the (pipe)line. The scenarios for transforming streams are endless.
In conclusion, map is a versatile operator which lets you transform a stream using a provided projection function. Whether it's mapping to a keycode, value updates from an input box, or reshaping an object, map will be one of the most used operators in your day-to-day RxJS toolbox.
Now, what if you want the whole student list, with name in capital letters and className is increased by 1, let's do this:
These two Qatar flights with slightly different times and different flight number must actually be the same flight, right?
value − It takes in the value kakım an argument and this value will be a map to the source value given.
map operator is used when we want to transform a stream into a value which is derece related to the emitted stream.
In plain language, this describes the action of on a specific element in its domain. Given a value for the element kakım input, say , the symbol also provides a concise way to represent the output of the function.
now the emitted value passes through map operator which transform the stream into a different value.
On the other hand map: Returns a list containing the results of applying the given transform function to each element in the original array.
We güç also pass pluck multiple values to grab a nested property within an object. For example, if we wanted to grab the nodeName from the target element on click, we could pass both of these properties to pluck in order:
Instead of our function returning a new object, we birey instead return just the property we need from that object: