how to check if an element has a class in javascript code example

Example 1: javascript check if element has class

if(document.getElementById("myElmentID").classList.contains("hidden")){
// I have the 'hidden' class
}

Example 2: check if a class exists javascript

const element = document.querySelector("#box");

element.classList.contains("active");

Example 3: how to check has class name in js?

element.classList.contains(className);Code language: CSS (css)

Example 4: check if has name javascript

function whatIsInAName(collection, source) {
  // "What's in a name? that which we call a rose
  // By any other name would smell as sweet.”
  // -- by William Shakespeare, Romeo and Juliet
  var srcKeys = Object.keys(source);

  return collection.filter(function(obj) {
    return srcKeys.every(function(key) {
      return obj.hasOwnProperty(key) && obj[key] === source[key];
    });
  });
}

// test here
whatIsInAName(
  [
    { first: "Romeo", last: "Montague" },
    { first: "Mercutio", last: null },
    { first: "Tybalt", last: "Capulet" }
  ],
  { last: "Capulet" }
);

Example 5: check if a class exists javascript

<div id="box" class="active"></div>