/**
* Utility function for retrieving the text value of an array of DOM nodes
* @param {Array|Element} elem
*/
getText = Sizzle.getText = function( elem ) {
    var node,
        ret = "",
        i = 0,
        nodeType = elem.nodeType;

    if ( !nodeType ) {
        // If no nodeType, this is expected to be an array
        for ( ; (node = elem[i]); i++ ) {
            // Do not traverse comment nodes
            ret += getText( node );
        }
    } else if ( nodeType === 1 || nodeType === 9 || nodeType === 11 ) {
        // Use textContent for elements
        // innerText usage removed for consistency of new lines (see #11153)
        if ( typeof elem.textContent === "string" ) {
            return elem.textContent;
        } else {
            // Traverse its children
            for ( elem = elem.firstChild; elem; elem = elem.nextSibling ) {
                ret += getText( elem );
            }
        }
    } else if ( nodeType === 3 || nodeType === 4 ) {
        return elem.nodeValue;
    }
    // Do not include comment or processing instruction nodes

    return ret;
};

jQuery的getText()方法源码,布布扣,bubuko.com

jQuery的getText()方法源码