Run results for: add seperator between array elements

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/115.0.0.0 Safari/537.36

Browser: Chrome 115

Operating system: Windows

Device Platform: Desktop

Date tested: one year ago

Tests:

flatmap
let inp = new Array(10000).fill(0) let sep = 1 inp = inp.flatMap((e, index) => index ? [sep, e] : e); console.log(inp.length, inp[0], inp[1], "...", inp.at(-2), inp.at(-1))
splice loop
let inp = new Array(10000).fill(0) let sep = 1 i = inp.length; while (--i) inp.splice(i, 0, sep); console.log(inp.length, inp[0], inp[1], "...", inp.at(-2), inp.at(-1))
reduce
let inp = new Array(10000).fill(0) let sep = 1 inp = inp.reduce((r, a) => r.concat(a, sep), []); inp.pop(); console.log(inp.length, inp[0], inp[1], "...", inp.at(-2), inp.at(-1))
copy loop
let inp = new Array(10000).fill(0) let sep = 1 let tar = new Array(inp.length * 2 - 1) for (let i = inp.length - 1; i > -1; --i) { tar[i * 2] = inp[i] tar[i * 2 - 1] = sep } inp = tar; console.log(inp.length, inp[0], inp[1], "...", inp.at(-2), inp.at(-1))