how to encode a string using the base64 code example

Example 1: convert an image into Base64 string using JavaScript

function getBase64Image(src, callback, outputFormat) {
      const img = new Image();
      img.crossOrigin = 'Anonymous';
      img.onload = () => {
        const canvas = document.createElement('canvas');
        const ctx = canvas.getContext('2d');
        let dataURL;
        canvas.height = img.naturalHeight;
        canvas.width = img.naturalWidth;
        ctx.drawImage(img, 0, 0);
        dataURL = canvas.toDataURL(outputFormat);
        callback(dataURL);
      };

      img.src = src;
      if (img.complete || img.complete === undefined) {
        img.src = "data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==";
        img.src = src;
      }
    }

Example 2: Encoding and Decoding Base64 Strings in Node.js

'use strict';

let data = 'stackabuse.com';
let buff = new Buffer(data);
let base64data = buff.toString('base64');

console.log('"' + data + '" converted to Base64 is "' + base64data + '"');