Pohyb

• hranice
• krok = -1*krok
• osa y
• souřadnice
• setTimeout

    <script src="rozmeryObrazovky.js"></script>     
    <script>  
      var x = 0;    
      var y = 0;
      var krok = 4;
      function posun() {
          var smile=document.getElementById('smile');
          x = x + krok; 
          
          smile.style.left = x + "px";
                  
      }
      setInterval("posun()", 25);
    </script> 
  

    <div style="height:100vh;">  
          <img src="img/smile.png" id="smile" width="64" height="64" style="position:absolute; left:0px; top:0px;">        
    </div>  
    <ul>
        <li>hranice</li>
        <li>krok = -1*krok</li>
        <li>osa y</li>
        <li>souřadnice</li>
        <li>setTimeout</li>
    </ul>