1) find duplicates in an array
---

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

<!-- [1,3] -->

// let newarr = new Set(arr)
// console.log(...newarr)

let n= arr.length;

let obj = {};
for(let p=0; p<n; p++){
if(obj[arr[p]]==undefined){
obj[arr[p]]=1;
}else{
obj[arr[p]]++;
}
}
console.log(obj)

// let sorted = arr.sort((a,b) => a-b)
// console.log(sorted)
// let count=0
// for(let p=0; p<n; p++){
// if(sorted[p] ==undefined){
// count++;
// }else{
// continue;

// }
// }
// console.log(sorted)

// for(var k in obj){
// console.log(k)
// }

---
2) React timer

---

import { useState } from "react";
export default function counter(){

const [count, setCount] = useState(0);
function handleClick(){
for(let p=count; p<count.length; p++){
setTimeout(() => {
setCount(count+1)
}, 3000)

}
}

return(

<div>

<h1>Count : {count}</h1>

<button onClick={handleClick}>start</button>
{/* <button onClick={handlePause}>Pause</button> */}

</div>
)
}