国产av日韩一区二区三区精品,成人性爱视频在线观看,国产,欧美,日韩,一区,www.成色av久久成人,2222eeee成人天堂

?? ???? ??

?? ??? ????? "document.write"? ?? ??? ???????. ??? ??? ????? ??? ?? ????

"document.write(sum)" ?? ?? ??? ????? ?? ???.

function add2(x,y)
{
  sum = x + y;   
return sum; //返回函數(shù)值,return后面的值叫做返回值。}

?? ??? ??? ?? ?? ??? ?? ?? ??? ?? ????. 

result = add2(3,4);//語句執(zhí)行后,result變量中的值為7。

??: ??? ????? ???? ???? ??? ??? ? ?? ??? ?? ????.


???? ??
||
<!DOCTYPE HTML> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>返回值函數(shù)</title> <script type="text/javascript"> function app2(x,y) { var sum,x,y; sum = x * y; return sum; } var req1 = app2(5,6); var req2 = app2(2,3); var sumq = req1 + req2; document.write("req1的值:"+req1+"<br/>"); document.write("req2的值:"+req2+"<br/>"); document.write(req1+"與"+req2+"和:"+sumq); </script> </head> <body> </body> </html>