Answers for "javascript detect id var id not defined"

3

checking if var is not defined js

if(typeof x !== 'undefined'){
  alert("Variable x is defined.");
}
Posted by: Guest on August-20-2020
7

javascript if undefined

if(typeof comment === 'undefined') {

  alert('Variable "comment" is undefined.');

} else if(comment === null){

  alert('Variable "comment" is null.');

}
Posted by: Guest on March-25-2020

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