Swapping Images in JavaScript

Swapping Images in JavaScript is simple, we just have to use the image src property along with the getElementById method.

document.getElementById("img1").src = "anotherImg.jpg";

Let’s say I have the following HTML code:

<div id="div1">
  <img id="img1" src="img.jpg">
</div>

To swap the image above to another image, we can use the src property. We can change the src of #img1 from img.jpg to anotherImg.jpg in the following JavaScript code:

document.getElementById("img1").src = "anotherImg.jpg";

Swapping Images in JavaScript with a Click

To change the source of an image we can combine the src property with an onclick event.

Let’s say we have the following HTML, similar to our example from above.

<div id="div1">
  <img id="img-1" src="http://theprogrammingexpert.com/wp-content/uploads/example-img1.png">
  <div id="click-me" onclick="swapImages()">Change image</div>
</div>

We have two images, example-img1.png is a picture of gears and example-img2.png is the same image, but with different colors.

We have added an onclick event to the #click-me div which will run a function where we can swap the images from the example-img1.png version to the example-img2.png version.

We can add a little more code so that whenever the button is pressed, it will swap the images.

Here is the function below that will accomplish this:

function swapImages(){
  //The if statement below is simply to check which image is currently showing
  //If 1 is found in the image source file name, it means example-img1.png is showing
  //So we need to show the other image
  if( document.getElementById("img-1").src.indexOf(1) > -1 ){
    document.getElementById("img-1").src = "http://theprogrammingexpert.com/wp-content/uploads/example-img2.png";
  } else {
    //Otherwise example-img1.png is currently showing, so we must swap it
    document.getElementById("img-1").src = "http://theprogrammingexpert.com/wp-content/uploads/example-img1.png";
  }
};

The final code and output for swapping images in JavaScript is below:

Code Output:

Change image

Full Code:

<style>#img-1 { height:100px; }</style>
<div id="div1">
  <img id="img-1" src="http://theprogrammingexpert.com/wp-content/uploads/example-img1.png">
  <div id="click-me" onclick="swapImages()">Change image</div>
</div>

<script>

function swapImages(){
  if( document.getElementById("img-1").src.indexOf(1) > -1 ){
    document.getElementById("img-1").src = "http://theprogrammingexpert.com/wp-content/uploads/example-img2.png";
  } else {
    document.getElementById("img-1").src = "http://theprogrammingexpert.com/wp-content/uploads/example-img1.png";
  }
};

</script>

Hopefully this article has helped you understand swapping images in JavaScript.