Attempting to change background color using JavaScript

Question

Attempting to change background color using JavaScript

As a newcomer to JavaScript, I am eager to learn how to use it to change the background color of an element by altering its class. Despite combining code snippets from various sources, my attempt is not yielding the desired results and the reason eludes me.

 
function myFunc() {
   var y = document.getElementById("bg-change1").getAttribute("class");
   if (y === "normal") {
     y = "active";
   } else {
     y = "normal";
   }
 }

.normal {
  background-color: white;
}

.active {
  background-color: green;
}

<body>
  <button onclick="myFunc()">click here</button>
  <div id="bg-change1" class="normal">
    <p>Lorem ipsum and etc</p>
  </div>
</body>

javascript html css

Answer 1

Answer №1

In order to complete the task successfully, it is imperative that you assign the value at the end rather than just retrieving it. The missing piece in your function is the line

document.getElementById("bg-change1").setAttribute("class",y);

which needs to be added at the end.

function myFunc() {
   var y = document.getElementById("bg-change1").getAttribute("class");
   if (y === "normal") {
     y = "active";
   } else {
     y = "normal";
   }
   document.getElementById("bg-change1").setAttribute("class",y);
 }

.normal {
  background-color: white;
}

.active {
  background-color: green;
}

<body>
  <button onclick="myFunc()">click here</button>
  <div id="bg-change1" class="normal">
    <p>Lorem ipsum and etc</p>
  </div>
</body>

Answer 2

In order to complete the task successfully, it is imperative that you assign the value at the end rather than just retrieving it. The missing piece in your function is the line

document.getElementById("bg-change1").setAttribute("class",y);

which needs to be added at the end.

function myFunc() {
   var y = document.getElementById("bg-change1").getAttribute("class");
   if (y === "normal") {
     y = "active";
   } else {
     y = "normal";
   }
   document.getElementById("bg-change1").setAttribute("class",y);
 }

.normal {
  background-color: white;
}

.active {
  background-color: green;
}

<body>
  <button onclick="myFunc()">click here</button>
  <div id="bg-change1" class="normal">
    <p>Lorem ipsum and etc</p>
  </div>
</body>

Answer 3

Answer №2

If you're looking to achieve this with vanilla JavaScript in a concise way, here's how you can do it:

function toggleClass() {
   var element = document.getElementById("bg-change1");
   element.classList.toggle("active");
}

Just ensure that the CSS selector order prioritizes the '.active' class over '.normal' for this effect to work as intended.

Answer 4

If you're looking to achieve this with vanilla JavaScript in a concise way, here's how you can do it:

function toggleClass() {
   var element = document.getElementById("bg-change1");
   element.classList.toggle("active");
}

Just ensure that the CSS selector order prioritizes the '.active' class over '.normal' for this effect to work as intended.

Answer 5

Answer №3

There's a more efficient way to toggle a class using the method below:

 
 function myFunc() {
   var y = document.getElementById("bg-change1");
   y.classList.toggle("active");
 }

.normal {
  background-color: white;
}

.active {
  background-color: green;
}

<body>
  <button onclick="myFunc()">click here</button>
  <div id="bg-change1" class="normal">
    <p>Lorem ipsum and etc</p>
  </div>
</body>

Answer 6

There's a more efficient way to toggle a class using the method below:

 
 function myFunc() {
   var y = document.getElementById("bg-change1");
   y.classList.toggle("active");
 }

.normal {
  background-color: white;
}

.active {
  background-color: green;
}

<body>
  <button onclick="myFunc()">click here</button>
  <div id="bg-change1" class="normal">
    <p>Lorem ipsum and etc</p>
  </div>
</body>

Answer 7

Answer №4

When you call getAttribute("class"), it retrieves the attribute's content at that specific moment. Since this content is a string, there is no connection to the element itself. Thus, reassigning <code>y

has no effect.

If you want to actually modify the attribute, you can use setAttribute("class", "active"). However, this solution may not be ideal as it restricts you to only one class and renders the "normal" class redundant.

Instead, apply default styles using a different selector (e.g., #bg-change1) and override properties as needed in the .active selector. This allows you to toggle between both states using document.getElementById("bg-change1").classList.toggle("active").

Answer 8

When you call getAttribute("class"), it retrieves the attribute's content at that specific moment. Since this content is a string, there is no connection to the element itself. Thus, reassigning <code>y

has no effect.

If you want to actually modify the attribute, you can use setAttribute("class", "active"). However, this solution may not be ideal as it restricts you to only one class and renders the "normal" class redundant.

Instead, apply default styles using a different selector (e.g., #bg-change1) and override properties as needed in the .active selector. This allows you to toggle between both states using document.getElementById("bg-change1").classList.toggle("active").

Answer 9

Answer №5

One way to manipulate a class name in JavaScript is by retrieving the current class of an element and then changing it based on certain conditions. However, this approach does not automatically update the class attribute of the element.

An alternative method to achieve the same result is by using a function like the following:

function myFunc() {
  var y = document.getElementById("bg-change1").getAttribute("class");
  if (y === "normal") {
    document.getElementById("bg-change1").classList.remove('normal');
    document.getElementById("bg-change1").classList.add('active');
  } else {
    document.getElementById("bg-change1").classList.remove('active');
    document.getElementById("bg-change1").classList.add('normal');
  }
}

Answer 10

One way to manipulate a class name in JavaScript is by retrieving the current class of an element and then changing it based on certain conditions. However, this approach does not automatically update the class attribute of the element.

An alternative method to achieve the same result is by using a function like the following:

function myFunc() {
  var y = document.getElementById("bg-change1").getAttribute("class");
  if (y === "normal") {
    document.getElementById("bg-change1").classList.remove('normal');
    document.getElementById("bg-change1").classList.add('active');
  } else {
    document.getElementById("bg-change1").classList.remove('active');
    document.getElementById("bg-change1").classList.add('normal');
  }
}

Answer 11

Answer №6

You have successfully retrieved the attribute, but now it's time to make changes and set it. Use the following code:

document.getElementById("bg-change1").setAttribute("class", y);

For example:

function updateClass() {
  var y = document.getElementById("bg-change1").getAttribute("class");
  if (y === "normal") {
    y = "active";
  } else {
    y = "normal";
  }
  document.getElementById("bg-change1").setAttribute("class", y);
}

.normal {
  background-color: white;
}

.active {
  background-color: green;
}

<button onclick="updateClass()">Click here</button>
<div id="bg-change1" class="normal">
  <p>Lorem ipsum and more</p>
</div>

Answer 12

You have successfully retrieved the attribute, but now it's time to make changes and set it. Use the following code:

document.getElementById("bg-change1").setAttribute("class", y);

For example:

function updateClass() {
  var y = document.getElementById("bg-change1").getAttribute("class");
  if (y === "normal") {
    y = "active";
  } else {
    y = "normal";
  }
  document.getElementById("bg-change1").setAttribute("class", y);
}

.normal {
  background-color: white;
}

.active {
  background-color: green;
}

<button onclick="updateClass()">Click here</button>
<div id="bg-change1" class="normal">
  <p>Lorem ipsum and more</p>
</div>

Attempting to change background color using JavaScript

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Answer №6

Similar questions

Having trouble constructing the Grand-Stack-Starter api because babel-node is not being recognized

Dealing with AJAX errors consistently in jQuery

AngularJS ng-repeat specific filter conditions

Vue caution: The reference to property or method "list" during render is not defined on the instance. Ensure that this property is reactive and properly declared

Combining an array of intricate data models to create

Adjust the position of an object in Three.js based on the scale of another object

What is the trick to creating uneven sides (lower left and lower right) with varying heights?

Leveraging jQuery to target elements with a minimum of two child elements

What are the time-saving benefits of utilizing semantic X/HTML in CSS development?

Apache causes HTML download tag to malfunction

Sprite hover image in IE9 not aligned properly or blurry by 1 pixel

Incorporating external JavaScript into a Rails application

Anomalous sorting methods found in JavaScript arrays

JavaScript will continue to process the submit to the server even after validation has been completed

Tips for making an input field that overlays text

What steps can I take to ensure that my $genderRadio variable is properly defined?

Encountered a problem while trying to fetch over 1000 records from the server using $

Tips for adjusting the height of MUI Date Picker to fit your preferences

"Sorry, cannot make a request for the relation field at

What methods can I use in JavaScript to modify input values and update them in my HTML output?