Discussion on: Better array concat...

[Sean Dinan]

I always forget about Array.flat(). There's definitely some Array.isArray(val) ? [...a, ...val] : [...a, val] lines that I could simplify with it. :)

[Eckehard]

Array.concat() does a similar job, it´s just a matter of taste:

let a = [1,2,3,4]
console.log(a.concat(5,6)) // -> [ 1, 2, 3, 4, 5, 6 ]

It is amazing what is already implemented in the Javascript Arrays. See this overview:

Array.prototype[@@iterator]()
Array.prototype.at()
Array.prototype.concat()
Array.prototype.copyWithin()
Array.prototype.entries()
Array.prototype.every()
Array.prototype.fill()
Array.prototype.filter()
Array.prototype.find()
Array.prototype.findIndex()
Array.prototype.findLast()
Array.prototype.findLastIndex()
Array.prototype.flat()
Array.prototype.flatMap()
Array.prototype.forEach()
Array.from()
Array.fromAsync()
Array.prototype.includes()
Array.prototype.indexOf()
Array.isArray()
Array.prototype.join()
Array.prototype.keys()
Array.prototype.lastIndexOf()
Array.prototype.map()
Array.of()
Array.prototype.pop()
Array.prototype.push()
Array.prototype.reduce()
Array.prototype.reduceRight()
Array.prototype.reverse()
Array.prototype.shift()
Array.prototype.slice()
Array.prototype.some()
Array.prototype.sort()
Array.prototype.splice()
Array.prototype.toLocaleString()
Array.prototype.toReversed()
Array.prototype.toSorted()
Array.prototype.toSpliced()
Array.prototype.toString()
Array.prototype.unshift()
Array.prototype.values()
Array.prototype.with()