Form.js

<form className="form-inline">
 <input
     type="text"
     className="form-control mb-2 mr-sm-2 mb-sm-0"
     placeholder="Name"
     ref={input => this.name = input}/>
 <div className="input-group mb-2 mr-sm-2 mb-sm-0">
   <input
     type="text"
     className="form-control"
     placeholder="Age"
     ref={input => this.age = input}/>
 </div>  
 <button 
     type="submit" 
     className="btn btn-primary">Save
 </button>
</form>