how to tell if a file exists in node code example

Example 1: use node js to check if a json file exists

const fs = require('fs')

const path = './file.txt'
//Async method
fs.access(path, fs.F_OK, (err) => {
  if (err) {
    console.error(err)
    return
  }

  //file exists
})

Example 2: check if file exists javascript

function executeIfFileExist(src, callback) {
    var xhr = new XMLHttpRequest()
    xhr.onreadystatechange = function() {
        if (this.readyState === this.DONE) {
            callback()
        }
    }
    xhr.open('HEAD', src)
}