我需要在以下代码中通过id或class获取元素，我相信它在function getActualWords(node) {部分，我尝试使用function getActualWords(".newsitem_text").get(0)但没有任何成功。该课程为newsitem_text，此处为小提琴http://jsfiddle.net/y9pw7z0p/4/，此处为代码：
// a simple utility function to get only the actual words
// from the supplied textNode (though this should work for
// elements also):
function getActualWords(node) {
// gets the textContent of the node,
// splits that string on one-or-more ('+')
// white-space characters ('\s');
// filters the array returned by split():
return node.textContent.split(/\s+/).filter(function (word) {
// word is the current array-element
// (a 'word') in the array over
// which we're iterating using
// Array.prototype.filter();
// here if the word, with leading
// and trailing white-space removed
// (using String.prototype.trim())
// has a length greater than 0
// (a falsey value) the word is kept
// in the array returned by filter:
return word.trim().length;
// note that negative numbers are
// also truthy, but no string can
// have a negative length; so the
// comparison is effectively, if
// not explicitly 'greater than zero'
// rather than simply 'not-zero'
});
}
// named function to insert the specified
// element after the nth word:
function insertElemAfterNthWord(opts) {
// defining the defaults for the function
// (which can be overridden via the opts
// Object):
var defaults = {
// the word after-which to insert the
// the new element:
'nth': 5,
// the text of the new element:
'elemText': 'new element',
// the type of element (note no '<' or '>'):
'elemTag': 'div'
};
// iterating over the supplied opts Object to update
// the defaults with the user-supplied options using
// for...in loop:
for (var prop in opts) {
// if the opts Object has a property and
// that property is not inherited from the
// prototype chain:
if (opts.hasOwnProperty(prop)) {
// we set the defaults property
// to the property-value held
// in the opts Object:
defaults[prop] = opts[prop];
}
}
// aliasing the defaults object (simply to save
// typing; this is not essential):
var d = defaults,
// ensuring that the supplied string,
// specifying the element-type has no
// '<' or '>' characters (to ensure validty
// this should be extended further to
// ensure only alphabetical characters are kept):
tag = d.elemTag.replace(/<|>/g, ''),
// creating the new element:
elem = document.createElement(tag);
// setting the textContent of the new element:
// ORIGINAL:// elem.textContent = d.elemText;
elem.innerHTML = d.elemText;
// ensuring that the d.nth variable is
// a number, not a string, in base-10:
d.nth = parseInt(d.nth, 4);
// if a node was specified:
if (d.node) {
// setting the 'n' variable to hold
// to the firstChild of the d.node:
var n = d.node.firstChild,
// using the utility function (above)
// to get an Array of only the actual
// words held in the node:
words = getActualWords(n),
// getting the number of words held
// in the Array of words:
wordCount = words.length;
// while (n.nodeType is not a textNode OR
// d.nth is a greater number than the number
// of words in the node) AND the node has
// a following sibling node:
while ((n.nodeType !== 3 || d.nth > wordCount) && n.nextSibling) {
// we update n to the next-sibling:
n = n.nextSibling;
// we get an array of words from
// newly-assigned node:
words = getActualWords(n);
// we update the wordCount, in
// order to progress through:
wordCount = words.length;
}
// if the number of words is less than
// the nth word after which we want to
// insert the element, we return from
// the function (doing nothing):
if (getActualWords(n).length < d.nth) {
return;
// otherwise:
} else {
// again we get an Array of actual words,
// we slice that Array and then get the
// last array-element from that array,
// using Array.prototype.pop():
var w = getActualWords(n).slice(0, d.nth).pop(),
// here we get the index of that word
// (note that this is naive, and relies
// upon the word being unique as a
// proof-of-concept; I plan to update later):
i = n.textContent.indexOf(w);
// we split the n textNode into
// two separate textNodes, at
// supplied index ('i + w.length');
// n remains the shortened 'first'
// textNode:
n.splitText(i + w.length);
// navigating to the parentNode, and
// using insertBefore() to insert the
// new element ('elem') before the
// next-siblin of the n textNode:
n.parentNode.insertBefore(elem, n.nextSibling);
// doing exactly the same, but adding a
// newly-created textNode (of a space character)
// between the 'n' textNode (which by definition
// ends without a space) and newly-inserted
// element:
n.parentNode.insertBefore(document.createTextNode(' '), n.nextSibling);
// joining adjacent, but unconnected,
// textNodes (n and the newly-inserted
// space character) together, to become
// a single node:
n.parentNode.normalize();
// returning the newly-created element
// so that it can be modified if required
// or simply cached:
return elem;
}
}
}
// calling the function, specifying the
// user-defined properties:
insertElemAfterNthWord({
// after the tenth word:
'nth': 10,
// the element-type (a span):
'elemTag': 'span',
// setting the text of that new element:
'elemText': '<img src="https://www.google.com.br/logos/doodles/2015/adolphe-saxs-201st-birthday-6443879796572160.2-res.png" />',
// specifying the node into which the element
// should inserted:
'node': document.querySelector('div > div')
// chaining the function, to use the Element.classList
// API to add the 'newlyAdded' class to the
// newly-created element:
}).classList.add('newlyAdded');
答案 0 :(得分：1)
你可以试试这个：
var elem = document.getElementsByClassName('.newsitem_text')[0];
getActualWords(elem);
getElementById只返回一个节点，但ByClassName返回一个节点列表，因此[0]将是第一个元素。 您也可以在评论中尝试@Matheus Lopes提出的方法。
var elem = document.querySelector('.newsitem_text');
getActualWords(elem);