Javascript for loop error

This is what I have:

function get_bad_changelist_authors() {
   var changelistAuthorDivs = $('div.bad_changelist_author');
   var changelistAuthors = [];

   for (var div in changelistAuthorDivs) {
      changelistAuthors.push($(changelistAuthorDivs[div]).text());
   }

   return changelistAuthors;
}

changeListAuthorDivs has n elements but for some reason it iterates n+1 times and initialized div to a string (ie. the string "lengt开发者_开发技巧h") on the last iteration. On the last iteration is where this loop has its error.

It seems you are using jQuery (please confirm). Then you can use .map() ^[docs] to achieve the same in a more concise way:

function get_bad_changelist_authors() {
   return $('div.bad_changelist_author').map(function() {
        return $(this).text();
   }).get();
}

Alternatively , use .each() ^[docs] if you deal with jQuery objects.

In general, @James is completely right, don't use for...in to iterate over arrays (see the warning here). In this case, the jQuery object has to be treated like an array.

JavaScript for...in loops will also iterate over properties of the object (length is a property of the object, which is why you end up with a div containing that string), which is not what you want. Use a normal for loop instead:

for(var i = 0; i < changeListAuthorDivs.length; i++) {
   //Do stuff
}

Try this

 for (var div in changelistAuthorDivs) {
     if(Object.prototype.hasOwnProperty.call(changelistAuthorDivs[div], div))
     changelistAuthors.push($(changelistAuthorDivs[div]).text());
  }