Question

这是Jquery里关于slideUp的方法，看得不是很明白，求高手解读？谢谢

function genFx( type, includeWidth ) {
var which,
attrs = { height: type },
i = 0;

// if we include width, step value is 1 to do all cssExpand values,
// if we don't include width, step value is 2 to skip over Left and Right
includeWidth = includeWidth? 1 : 0;
for( ; i < 4 ; i += 2 - includeWidth ) {
which = cssExpand[ i ];
attrs[ "margin" + which ] = attrs[ "padding" + which ] = type;
}

if ( includeWidth ) {
attrs.opacity = attrs.width = type;
}

return attrs;}

Answer 1

要翻译么？

追问

他的循环是怎么完成的。slideUp里面是通过修改height的值，慢慢地展开的，而我现在想修改css里面的top，慢慢地展开的，所以想知道它的怎么完成这种效果的