<script?type="text/javascript">
var?main?=?document.body;
//創(chuàng)建鏈接
function?createa(url,text)
{
????var?a?=?document.createElement("a");
????a.setAttribute("href",url);
????a.style.color?=?"green";
????main.appendChild(a);
????var?txt?=?document.createTextNode(text);
????a.appendChild(txt);
}
//?調(diào)用函數(shù)創(chuàng)建鏈接
var?input?=?document.createElement("input");
input.setAttribute("type","button");
input.setAttribute("value","點擊創(chuàng)建鏈接");
input.onclick?=?function?(){
????createa("http://idcbgp.cn","慕課網(wǎng)");
}
main.appendChild(input);
</script>

為什么onclick不能直接onclick =?createa("http://idcbgp.cn","慕課網(wǎng)");??

網(wǎng)上搜了說 onclick =?createa ; 這樣才是正確調(diào)用方法. 就好像window.onload也是 window.onload = 函數(shù)名 或?window.onload = function(){ 函數(shù)名(參數(shù)); } 而不是 window.onload = 函數(shù)名() ;?

所以哪類對象調(diào)用函數(shù)是這樣的規(guī)則呢?