JSFiddle - React, Tailwind, and code Playground

by mrtoxas

JavaScript

const arr = [1, 1, 2, 3, 4, 5, 6, 7, 7, 8, 9]

const res = arr.reduce((acc, val) => {  
  if (acc.indexOf(val) < 0 )  acc.push(val);
  return acc;
}, []);

console.log(res)