document.onkeydown=move;
function move() {
var code = event.keyCode;
var direction;
if(code == 37){
direction = 3;
}
else if (code ==38){
direction = 4;
}
else if (code ==39){
direction = 1;
}
else if (code == 40){
direction = 2;
} console.log(direction);
return direction; //怎么实现函数外部得到direction值
}
var sd =move();
console.log(sd);
};