语法

Question

   var ret = [] 
             ,xresult = document.evaluate(exp, rootEl, null,
                         XPathResult.UNORDERED_NODE_ITERATOR_TYPE, null)
             ,result = xresult.iterateNext();
   while (result) {
     ret[ret.length]= result;
     result = xresult.iterateNext();
   }

谁能给我解释一下 ret = [],..,... 的语法是什么？正在初始化数组？

Answer 1

你是对的。这段代码:

var ret = [] 
             ,xresult = document.evaluate(exp, rootEl, null,
                         XPathResult.UNORDERED_NODE_ITERATOR_TYPE, null)
             ,result = xresult.iterateNext();

可以重写为:

var ret = [];
var xresult = document.evaluate(exp, rootEl, null,
                         XPathResult.UNORDERED_NODE_ITERATOR_TYPE, null);
var result = xresult.iterateNext();

var foo = []; 将 foo 初始化为空数组。