how to get class element in javascript using queryselector code example

Example 1: js queryselector

const content = document.querySelector('.content');

const towns = ['Helsinki', 'Espoo', 'Vantaa'];

towns.forEach(city => {
    content.innerHTML += `<p>${city}</p>`;
});

Example 2: queryselector function in javascript

/*The querySelector() method returns the first element that matches a specified 
CSS selector(s) in the document. Note: The querySelector() method only returns 
the first element that matches the specified selectors. To return all the 
matches, use the querySelectorAll() method instead.*/

// for example 

//for class
document.querySelector(".ClassName")

// for id 
document.querySelector("#ID")

// etc.