javascript笔记04：let语句 和 yield语句 和 with语句

1.yield语句：

<script  type="application/javascript; version=1.7">
     function generator() {
                 var i = 0;
                 while(i<10) {
                   //产生输出，这里的yield相当于return
                  yield i;
                  i++;
           }
     }

       //获取产生器

      var g = generator();
      //迭代
      for(var j=0; j<10; j++) {
        document.write(g.next()+"<br>");
   }

</script>

2.with语句

<script>
var rightNow = new Date();
with(rightNow) {
     document.write(getDay()+"<br>");
     document.write(getMonth()+1+"<br>");
     document.write(getFullyear()+"<br>");
}</script>

等价于：

<script>
var rightNow = new Date();
document.write(rightNow.getDay()+"<br>");
document.write(rightNow.getMonth()+1+"<br>");
document.write(rightNow.getFullYear()+"<br>");
</script>