function changelocation1(select3,localtionid1){
select3.length = 0;
var loc1 = localtionid1;
select3.options[select3.length] = new Option("","");
for(var j=0; j<subcat1.length;j++){
if(null == loc1 || loc1 == ""){
select3.options[select3.length] = new Option(subcat1[j][0],subcat1[j][0]);
}else if(loc1 == subcat1[j][1]){
select3.options[select3.length] = new Option(subcat1[j][0],subcat1[j][0]);
}
}
}
js中options也就是红色部分索引值是怎么改变的在代码中并没有发现类似++的代码,那么它的索引值是怎么改变的
select3.length = 0;
var loc1 = localtionid1;
select3.options[select3.length] = new Option("","");
for(var j=0; j<subcat1.length;j++){
if(null == loc1 || loc1 == ""){
select3.options[select3.length] = new Option(subcat1[j][0],subcat1[j][0]);
}else if(loc1 == subcat1[j][1]){
select3.options[select3.length] = new Option(subcat1[j][0],subcat1[j][0]);
}
}
}
js中options也就是红色部分索引值是怎么改变的在代码中并没有发现类似++的代码,那么它的索引值是怎么改变的
你每次触发onchange事件是时候就给它清空了options
这一行,就是增加了一个option,length当然是加了1
this.length++;
}
var obj = [];
obj[obj.length] = new sl();
obj[obj.length] = new sl();
obj[obj.length] = new sl();
obj[obj.length] = new sl();
obj[obj.length] = new sl();
alert(obj.length)