<!DOCTYPE HTML><html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"><title>計(jì)時(shí)器</title></head><script type="text/javascript">? var num=0;? function startCount() {? ? document.getElementById('count').value=num;? ? num=num+1;? ? setTimeout("startCount()",1000)?? }? ? setTimeout("startCount()",1000)?</script></head><body><form><input type="text" id="count" onClick="startCount()"/></form></body></html>在function的大括號(hào)外再寫(xiě)一遍?setTimeout("startCount()",1000)計(jì)時(shí)器才會(huì)正常運(yùn)行但是在form里加個(gè)button 把startCount()放在button里?就只寫(xiě)一遍就可以 這是為什么？?</head><script type="text/javascript">? var num=0;? function startCount() {? ? document.getElementById('count').value=num;? ? num=num+1;? ? setTimeout("startCount()",1000)?? }? ? setTimeout("startCount()",1000)?</script></head><body><form><input type="text" id="count" /><input type="button" value="開(kāi)始計(jì)時(shí)" onClick="startCount()"/></form></body>就像上面的代碼 點(diǎn)開(kāi)始計(jì)時(shí)就可以計(jì)時(shí)了求解答
關(guān)于計(jì)時(shí)器 為什么setTimeout函數(shù)要寫(xiě)兩遍？
慕瓜1750935
2016-06-07 16:33:21