@StrangerA #4 你都 lodash 了，不直接用 chunk

let n = arr.length, f = fixed, pad = {};
let result = new Array(Math.ceil(n/f)).fill(0).map((_,i)
    =>arr.slice(i*f,i*f+f).concat(new Array(i*f+f>n?fixed-n%fixed:0).fill(pad)));

https://i.imgur.com/qIuvFSk.png