Basic usage of stepper

usage-stepper.js

// Select your stepper element.  
var stepperElement = document.querySelector('ul.mdl-stepper');
var Stepper;

// Check if MDL Component Handler is loaded.
if (typeof componentHandler !== 'undefined') {
  // Get the MaterialStepper instance of element to control it.          
  Stepper = stepperElement.MaterialStepper;
  // Moves the stepper to the next step for test.
  Stepper.next();
} else {
  // Material Design Lite javascript is not loaded or for another  
  // reason MDL Component Handler is not available globally and
  // you can't use (register and upgrade) Stepper component at this point.
}