JSFiddle - React, Tailwind, and code Playground

by ChrisStanyon

JavaScript

function isset (accessor) {
  try {
    // Note we're seeing if the returned value of our function is not
    // undefined
    return typeof accessor() !== 'undefined'
  } catch (e) {
    // And we're able to catch the Error it would normally throw for
    // referencing a property of undefined
    return false
  }
}



let rr6;
alert(isset(rr6)); //Should return true

rr6 = "Hello world";
alert(isset(rr6)); //Should return true

let rr7 = [];
rr7['t1'] = 72;

alert(isset(rr7)); //Should return true
alert(isset(rr7['t1'])); //Should return true
alert(isset(rr7['t2'])); //Should return false

alert(isset(rr8)); //Should return false

let $rr8;
$rr8 = "By World";
alert(isset($rr8));

//<input type="text" id="txtrr9" />
alert(isset($("#txtrr9").attr("id")));  // Should return true
alert(isset($("#txtrr9").data("guid")));  // Should return false