zhe 有何意義
function parents(elem){
? var matched = [];
? while ( (elem = elem[ 'parentNode' ]) && elem.nodeType !== 9 ) {
??? if ( elem.nodeType === 1 ) {
????? matched.push( elem );
??? }
? }
? return matched;
}
函數(shù)中加粗的句子為何！==9，而不是其他，或者省略elem.nodeType !== 9
2017-10-12
9代document節(jié)點(diǎn),它是最高節(jié)點(diǎn),如果不做判斷則無法繼續(xù)往上查找父級(jí)節(jié)點(diǎn)