How to preview multiple images before uploading it to server?

Previewing multiple images before uploading them to the server can be achieved using JavaScript and the HTML5 **FileReader** API. Here's an example:

1. Add an input element for file selection: In your HTML file, add an input element with a type of **file** and the **multiple** attribute that allows the user to select multiple image files:

<input type="file" id="imageInput" multiple>

1. Add an image container element: Add a container element to your HTML file that will be used to display the previews of the selected images:

<div id="imagePreviewContainer"></div>

1. Attach a change event to the input element: In your JavaScript file, attach a change event to the input element that triggers when the user selects files:

document.querySelector('#imageInput').addEventListener('change', function () {
  previewImages(this);
});

1. Implement the **previewImages** function: Implement the **previewImages** function that uses the **FileReader** API to read the selected image files and add image elements to the image container element to display the previews:

function previewImages(input) {
  document.querySelector('#imagePreviewContainer').innerHTML = '';
  for (var i = 0; i < input.files.length; i++) {
    var reader = new FileReader();
    reader.onload = function (e) {
      var img = document.createElement('img');
      img.setAttribute('src', e.target.result);
      document.querySelector('#imagePreviewContainer').appendChild(img);
    };
    reader.readAsDataURL(input.files[i]);
  }
}

By following these steps, you should be able to preview multiple images before uploading them to the server. The image previews are achieved by using the **FileReader** API to read the contents of the selected image files and adding image elements to the image container element to display the previews.