Answers for "how to check if variable is undefined javascript"

Javascript

javascript check if not undefined

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

Posted by: Guest on October-23-2019

test if is undefined javascript

let id;

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

Posted by: Guest on August-10-2020

javascript check if boolean is undefined

if (typeof myFlag !== "undefined") {
  // comes here whether myFlag is true or false but not defined
}

Posted by: Guest on May-02-2020

js check if undefined

let foo = undefined
//will return true
typeof foo === 'undefined'

Posted by: Guest on July-15-2020

-1

undefined javascript check

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

Posted by: Guest on March-30-2020

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