how to delay function execution in javascript code example

Example 1: timer in javascript

//single event i.e. alarm, time in milliseconds
var timeout = setTimeout(function(){yourFunction()},10000);
//repeated events, gap in milliseconds
var interval = setInterval(function(){yourFunction()},1000);

Example 2: javascipt delay

function sleep(ms) {
  return new Promise(resolve => setTimeout(resolve, ms));
}

console.log("Hello");
sleep(2000).then(() => { console.log("World!"); });

Example 3: javascipt delay

async function delay(delayInms) {
      return new Promise(resolve  => {
        setTimeout(() => {
          resolve(2);
        }, delayInms);
      });
    }
    async function sample() {
      console.log('a');
      console.log('waiting...')
      let delayres = await delay(3000);
      console.log('b');
    }
    sample();