Javascript getelementsbyclassname method solution

  node.js, question
function getElementsByClassName(node,classname){
 if(node.getElementsByClassName){
 return node.getElementsByClassName(**classname**);
 } else {
 var results=new Array();
 var elems=node.getElementsByTagName("*");
 for(var i=0;   i<elems.length;  I plus)
 if(elems[i].className.indexOf(classname) !  =-1) {
 results[result.length]=elems[i];
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 return results;
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 The bold part of the code parameters are What Do You Mean?  The parameter of getElementsByClassName method should be a string. Why is there no quotation mark in parentheses?

The lower version of ie browser does not support the getElementsByClassName method. The code above encapsulates a good compatibility getElementsByClassName, which can be used in all browser versions.
For example, if you want to get the element in the whole page, the first parameter is document, and the second parameter is the classname of the element you want to get.
For example, if you want to obtain an element in ul, the first parameter is a reference to ul. this reference can be obtained by other methods such as getElementById or getElementsByTagName. the second parameter is the same as above