javascipt delay

1setTimeout(function () {
2
3//to do..
4
5}, 1000);
6

1function sleep(ms) {
2  return new Promise(resolve => setTimeout(resolve, ms));
3}
4
5console.log("Hello");
6sleep(2000).then(() => { console.log("World!"); });
7

1    async function delay(delayInms) {
2      return new Promise(resolve  => {
3        setTimeout(() => {
4          resolve(2);
5        }, delayInms);
6      });
7    }
8    async function sample() {
9      console.log('a');
10      console.log('waiting...')
11      let delayres = await delay(3000);
12      console.log('b');
13    }
14    sample();