Day 8 of 14 30 minmap / filter / reduceSpreadDestructuring
Store lists of values and work with them. Add and remove items, find things, and transform whole lists with map, filter and reduce, the methods you'll use in almost every JavaScript program.
By the end of today you can
- Create arrays, read items by index and check the length
- Add and remove items with push, pop, shift, unshift and splice
- Find items with includes, indexOf, find and some
- Transform arrays with map, filter and reduce
- Know which methods change the array and which return a new one
What's inside
- 6 sections
- 3 diagrams and mind maps
- 6 code examples you can run
- 5-question quiz
- 1Creating and reading arrays
- 2Adding and removing
- 3Finding things
- 4map, filter and reduce
- 5Sorting (and a trap)
- 6Changing vs copying
Sign in free to read this lesson
Get the full lesson with diagrams, runnable code and the quiz. Your progress is saved across devices.
Sign in free