javascript - settimeout中傳入參數的問題
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<script type="text/javascript">
window.onload = function(){
var nav_level_1 = document.getElementsByClassName("nav_level_1")[0],
lis_1 = nav_level_1.children;
for(var i = 0;i < lis_1.length;i++){
lis_1[i].onmouseover = function(){
var ul = this.getElementsByClassName("nav_level_2")[0];
addHeight(ul);
}
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function addHeight(ul){
var ul_height = ul.offsetHeight;
ul_height++;
if(ul_height <= 95){
ul.style.height = ul_height + "px";
setTimeout("addHeight('"+ul+"')",10);
}else{
return;
}
}
</script>
</body>用settimeout寫二級選單的展開收縮，在settimeout中傳入一個帶有參數的函數，不知道怎麼傳，影片中是這樣寫的setTimeout("addHeight('" ul "')",10 )但是不太正常，請問是什麼原因？
