js not undefined code example

Example 1: js if not undefined

if (typeof myVar !== "undefined") {
    console.log("myVar is DEFINED");
}

Example 2: javascript typeof undfined

var x;
if (typeof x === 'undefined') {
   // these statements execute
}

Example 3: test if is undefined javascript

let id;

if(typeof id === 'undefined') {
    console.log("id is undefined...");
}

Example 4: checking if var is not defined js

if(typeof x !== 'undefined'){
  alert("Variable x is defined.");
}

Example 5: if not undefined javascript

if(typeof myVar !== "undefined")

Example 6: undefined javascript check

if(undefinedElement === null) {
	console.log("Element is undefined");
}