SOURCE

reducer = (state = [],action) => {
  if (action.type === 'split_string'){
    return action.payload.split('');
  }else if (action.type === 'add_character'){
    return [...state,action.payload ];
  }
  return state;
  
}
function render(){
  document.querySelector('body').innerHTML = store.getState();
}
var store = Redux.createStore(reducer);
store.subscribe(render);
render();
action = {
  type : 'split_string',
  payload : 'abcd'
}
store.dispatch(action);

action2 = {
  type: 'add_character',
  payload :'e'
}
store.dispatch(action2);