id | compare | mainCompare | focusOn | video | learnBackAbout | lesson | title | layout | class | preview_image | preview_image_alt | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
filter |
|
filter |
map |
239108249 |
fromEvent |
6 |
Map vs Filter - Project function vs Predicate |
default |
post |
filter/content_preview.jpg |
Filter a stream |
In the video example, ▬ isEven
accepts a number
as an argument:
- If it is an even number, it returns
✔ true
- Otherwise, it returns
✘ false
It is used as:
- a project function on
❚ map
- a predicate function on
❚ filter
A predicate returns ✔ true
or ✘ false
.