zhe 有何意义
function parents(elem){
var matched = [];
while ( (elem = elem[ 'parentNode' ]) && elem.nodeType !== 9 ) {
if ( elem.nodeType === 1 ) {
matched.push( elem );
}
}
return matched;
}
函数中加粗的句子为何！==9，而不是其他，或者省略elem.nodeType !== 9
