call是js自带的函数？？？？ javascript 回调函数

Question

var timer = setInterval(function(){          var t = new Date() - startTime;         var d = time;         if ( t >= d )         {                 t = d;                 clearInterval( timer );                 callback();         } //callback()放于此处会导致少执行一次for循环         for ( var key in mJson )         {                 var b = startVal[key];                 var c = endVal[key] - b;                 var s = Tween[cv]( t , b , c , d );                 obj.style[key] = s + 'px';         } },13);/////改写为 var timer = setInterval(function(){          var t = new Date() - startTime;         var d = time;         if ( t >= d )         {                 t = d;                 clearInterval( timer );         }         for ( var key in mJson )         {                 var b = startVal[key];                 var c = endVal[key] - b;                 var s = Tween[cv]( t , b , c , d );                 obj.style[key] = s + 'px';         }         if ( t == d )         {                  callback && callback.call(obj);         } },13);//callback是自命名的函数可换为wangdachui

Answer 1

是的。 call是js自带的函数哦。