js两种拼接字符串的简单方法(必看)

function(msgArr) {
  var len = msgArr.length;
  var n = 0 ;
  var htmlSpan = "";
  for (var j = 0; j < len - 1; j++) {
    htmlSpan += '<span>?</span>';
  }
  htmlSpan += '<span class="on">?</span>';
  var imgs = [];
  var img = [];
  img[0] = '<a href="' + ctx + '/webservice/dish/detail?id=';
  img[1] = '#';
  img[2] = '"><img src="';
  img[3] = '#';
  img[4] = '"></a>';

  for (var i = 0; i < len; i++) {
    img[1] = msgArr[i].id;
    img[3] = msgArr[i].pic;
    imgs.push(img.join(""));
  }
  $("#banner_list").html(imgs.join(""));
  $(".dots").html(htmlSpan);
}