题解 | #移动控制#

 let target=document.querySelector('.current')       
 target.classList.toggle('current')        
 switch(code){            
case 37:               
 	(target.previousSibling || target.parentNode.lastChild).classList.toggle('current')                	break;            
case 39:                
	(target.nextSibling || target.parentNode.firstChild).classList.toggle('current');             		break;            
case 38:           	(target.parentNode.previousElementSibling&&target.parentNode.previousElementSibling.children[target.cellIndex] || target.parentNode.parentNode.lastElementChild.children[target.cellIndex]).classList.toggle('current')                break;            
case 40:               (target.parentNode.nextElementSibling&&target.parentNode.nextElementSibling.children[target.cellIndex] || target.parentNode.parentNode.firstElementChild.children[target.cellIndex]).classList.toggle('current')                
break;        }    };}