How to take title of an image and it set as a alt tag using Javascript?

You can take the title of an image and set it as the alt tag using JavaScript by first selecting the image and then accessing its title and alt attributes.

Here is an example:

// Select the image
var img = document.getElementById("my-image");

// Get the title of the image
var imgTitle = img.getAttribute("title");

// Set the alt tag to the title of the image
img.setAttribute("alt", imgTitle);

This code uses the getElementById method to select the image with the id "my-image". The getAttribute method is used to access the title of the image and then the setAttribute method is used to set the alt tag to the title of the image.

You could also use other DOM traversal methods such as querySelector or getElementsByClassName to select the image, as long as you have proper image selector.

Here is an example of a JavaScript function that dynamically selects all images on a webpage and sets the alt tag to the title of the image if the alt tag is missing:

function setAltTags() {
  // Get all images on the page
  var images = document.getElementsByTagName("img");
  
  // Loop through each image
  for (var i = 0; i < images.length; i++) {
    var img = images[i];
    
    // If the image does not have an alt tag, add the title as the alt tag
    if (!img.hasAttribute("alt")) {
      var imgTitle = img.getAttribute("title");
      if (imgTitle) {
        img.setAttribute("alt", imgTitle);
      }
    }
  }
}

This function uses the getElementsByTagName method to select all images on the webpage and then loops through each image. If an image does not have an alt attribute, it gets the title attribute of the image and sets it as the alt attribute.

You can call this function on page load or on certain event like click or on certain other events as per your requirement.

 window.addEventListener("load", setAltTags);

This will make sure that alt tags will be added to all images on page load.