let arr=[1,1,2,2,3,2,4,5]; function uniqueArray(arr) { let obj={}; let result=[]; for(let i=0;i<arr.length;++i) { if(!obj.hasOwnProperty(arr[i])) { result.push(arr[i]); obj[arr[i]]=1; } } return result; } console.log(uniqueArray(arr));