RxJs will only consider the initial occurrence of a specific type of value and ignore any subsequent occurrences until a different type of value is encountered

Question

RxJs will only consider the initial occurrence of a specific type of value and ignore any subsequent occurrences until a different type of value is encountered

I'm faced with a situation where I need to extract the first occurrence of a specific value type, followed by the next unique value of a different type.

Let's break it down with an example:

of(1,1,1,1,2,3,4)
.pipe(
    // some operators
)
.subscribe(val => console.log(val);

In this case, my desired output is 1,2,3,4

It's important to note that the first "1" in the output should be from the original source and not the one right before "2."

How can I accomplish this task using rxjs operators?

javascript typescript rxjs rxjs-pipeable-operators

Answer 1

Answer №1

If you're searching for a specific operator, look no further than distinctUntilChanged(). Here's an example of how to use it:

of(1,1,1,1,2,3,4).pipe(
    distinctUntilChanged()
).subscribe(value => console.log(value));

With this code, the output will be 1, 2, 3, 4. Keep in mind that previously occurring values may appear again, so it behaves differently from a DISTINCT clause in SQL (for instance, 1,1,2,3,4,1 would result in 1, 2, 3, 4, 1).

Answer 2

If you're searching for a specific operator, look no further than distinctUntilChanged(). Here's an example of how to use it:

of(1,1,1,1,2,3,4).pipe(
    distinctUntilChanged()
).subscribe(value => console.log(value));

With this code, the output will be 1, 2, 3, 4. Keep in mind that previously occurring values may appear again, so it behaves differently from a DISTINCT clause in SQL (for instance, 1,1,2,3,4,1 would result in 1, 2, 3, 4, 1).

Answer 3

Answer №2

When presented with the sequence 111223111,

To obtain 123, apply the distinct operator.

To achieve 1231, utilize the distinctUntilChanged operator.

Answer 4

When presented with the sequence 111223111,

To obtain 123, apply the distinct operator.

To achieve 1231, utilize the distinctUntilChanged operator.

RxJs will only consider the initial occurrence of a specific type of value and ignore any subsequent occurrences until a different type of value is encountered

Answer №1

Answer №2

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