javascript check if var is undefined empty or null code example

Example 1: javascript check if undefined or null

if( typeof myVar === 'undefined' || myVar === null ){
    // myVar is undefined or null
}

Example 2: javascript check if variable is empty

if( value ) {
  //
}

/**
* This will evaluate to true if value is not:
* null
* undefined
* NaN
* empty string ("")
* 0
* false
*/