More ways to filter data
In RxJS, we also have other operators to filter data. In this section, we will learn about the following operators:
first()
take()
takeLast()
takeWhile()
skip()
skipWhile()
We can use these operators when we are interested only in a subset of data from an observable.
Note
There are other operators to filter data on RxJS but these are the most common ones.
The first() operator
The first()
operator returns a new observable containing only the first element in an observable which satisfies a given condition. This operator has the following signature:
observable.first([condition],[context],[defaultValue]);
All parameters are optional:
condition
: This is the function which the value must satisfy to be retrievedcontext
: This is an argument used in the given conditional functiondefaultValue
: This is a value used as the default if the observable is exhausted and no item satisfies the given condition
If no condition is supplied, this operator returns the first element in the Observable...