Array Methods Reference

Iteration

`arr.forEach((v, i) => {})`	Iterate (no return value)
`arr.map(v => v * 2)`	Transform each element
`arr.filter(v => v > 0)`	Keep matching elements
`arr.reduce((acc, v) => acc + v, 0)`	Reduce to single value
`arr.find(v => v.id === 1)`	Find first match
`arr.findIndex(v => v > 5)`	Find first match index
`arr.every(v => v > 0)`	All match condition?
`arr.some(v => v > 0)`	Any match condition?

Mutation

`arr.push(item)`	Add to end
`arr.pop()`	Remove from end
`arr.unshift(item)`	Add to front
`arr.shift()`	Remove from front
`arr.splice(i, 1, newItem)`	Remove/insert at index
`arr.sort((a,b) => a-b)`	Sort in-place
`arr.reverse()`	Reverse in-place

Non-mutating

`arr.slice(1, 3)`	Extract subarray
`[...arr1, ...arr2]`	Concat (spread)
`arr.flat(depth)`	Flatten nested arrays
`arr.flatMap(v => [v, v*2])`	Map + flatten
`arr.includes(val)`	Check if contains value
`arr.indexOf(val)`	Find index
`Array.from({length:5}, (_,i) => i)`	Create array by index