What’s on the JS Array Methods poster
A 10-row table: Method · Returns · Mutates?.
The methods that cover almost all day-to-day array work.
- map(fn) — New array, same length — no
- filter(fn) — New, shorter array — no
- reduce(fn, init) — One value — no
- find(fn) — First match or undefined — no
- some / every — Boolean — no
- slice(a, b) — A copy of a range — no
- sort(fn) — The sorted array — YES
- splice(i, n) — Removed items — YES
- push / pop / shift — Length or item — YES
- flat / flatMap — New flattened array — no
sort() without a comparator sorts as strings: [10, 9, 1] becomes [1, 10, 9]. Always pass (a, b) => a - b for numbers.
Questions about the JS Array Methods poster
- What’s on the JS Array Methods poster?
- A 10-row table: Method · Returns · Mutates?. The methods that cover almost all day-to-day array work. map(fn) — New array, same length — no; filter(fn) — New, shorter array — no; reduce(fn, init) — One value — no; find(fn) — First match or undefined — no; some / every — Boolean — no; slice(a, b) — A copy of a range — no; sort(fn) — The sorted array — YES; splice(i, n) — Removed items — YES; push / pop / shift — Length or item — YES; flat / flatMap — New flattened array — no. sort() without a comparator sorts as strings: [10, 9, 1] becomes [1, 10, 9]. Always pass (a, b) => a - b for numbers.
- Who is the JS Array Methods poster for?
- JS Array Methods belongs to the Computing section rather than to a school year, because computing is not something one grade owns. Anyone learning languages can pin it up — a beginner, a student mid-course, or someone revising years later.
- When should you use the JS Array Methods poster?
- Check the mutates column before chaining. Half of these change the array in place. A wall chart earns its place by being glanceable from where the work is happening, so JS Array Methods belongs on the wall where that computing work actually happens, within glancing distance, rather than filed away.
- What other posters go with JS Array Methods?
- REST API Design, Bash Scripting and Error Handling sit alongside JS Array Methods in the Computing section. Printed together they make a wall rather than a single sheet, which is how a reference set actually gets used.REST API DesignBash ScriptingError Handling
- Is the JS Array Methods poster free to download and print?
- Yes. JS Array Methods downloads as a free PDF with no account, no email and no watermark, like everything else in the Computing section. Print as many copies as you like for a home, a classroom, a library or a tutoring group; reselling the file is the only thing the licence rules out.Read the licence
- What size does the JS Array Methods poster print at?
- JS Array Methods is a vector PDF laid out for US Letter, and prints on A4 with Fit to page — the same file, no separate download. Because every mark on it is drawn rather than photographed, it stays sharp enlarged to A3, A2 or A1 at a copy shop. Colour carries emphasis only, so a greyscale print of JS Array Methods loses nothing.Printing guide
Related posters
Charts that sit alongside JS Array Methods on the same wall.
Browse every Computing poster, or start from the full catalogue.