JSFiddle - React, Tailwind, and code Playground

JavaScript

function ps (n) {
  if (!(n%2)) {
  	console.log('n 要是奇數');
    return;
  }
  let out = [];
  let arr = Array(n).fill('*');
  let arr2 = Array(n).fill(' ');
  let cnt = 0;
  while (cnt < n) {
  	out.push(arr2.slice(0, cnt/2).concat(arr.slice(0, n-cnt)).concat(arr2.slice(0, cnt/2)).join(''));
    cnt+=2;
  }
  	cnt-=4;
  while (cnt >= 0) {
  	out.push(arr2.slice(0, cnt/2).concat(arr.slice(0, n-cnt)).concat(arr2.slice(0, cnt/2)).join(''));
  	cnt-=2;
  }
  console.log(out.join('\n'));
}
ps(9);