“javaScript получить элемент по классу DOMLIST неопределен” Ответ

javaScript получить элемент по классу DOMLIST неопределен

// When querySelector doesn’t find a matching selector, 
// the value of the variable will be : null .
// So use queryselector not multiple el selector like getElementByClassName

// To check if the DOM elements innerText is empty without errors use this:
	var ismissingElement1 = document.getElementByClassName('myclass'); //with no dots
    var ismissingElement = document.querySelector('.myclass'); // with dot
    
	//CHECK FOR ANGULARJS POPULATED DOM (i.e. every 5 sec)
	if( !ismissingElement1){ ismissingElement[0].length } //CHECK NOT POSSIBLE : undefined DOM list
	//all this inside the brackets are not working: !== null or !==undefined

    if (!ismissingElement){ alert ('this works! myclass element is present') }; //CHECK OK