sabrinaluo

var array = ["lily", "tom", "lucy"];
var ele1 = "lily";
var ele2 = "lucy";
var ele3 = "jack";

array.indexOf(ele1); // return 0
array.indexOf(ele2); // return 2

array.indexOf(ele3); //return -1; NOTE: element is not in the array if return -1

sabrinaluo

<ul>
  <li>item1</li>
  <li class="active">item2</li>
  <li>item3</li>
</ul>

<script>
  $(ul).find(".active").index(); //return 1
</script>

sabrinaluo

<style>
  img{
    border-radius:10px;
  }
</style>
<img src="xx.jpg">

sabrinaluo

//查找同级元素
$("#id").next(); // 下一个同级元素
$("#id").prev(); // 前一个
$("#id").nextAll("div"); // 所有该元素之后的同级div元素
$("#id").prevAll("div");
$("#id").prevAll("div").andSelf(); //所有该元素之前的同级div元素及该元素本身

sabrinaluo

<style>
  div{
    height:100px;
    width:100px; /*宽高必须相等*/
    overflow:hidden; /*隐藏超出div的部分*/
    border-radius:50%;/*圆角为宽高的50%*/
  }
</style>
 
<div>

sabrinaluo

$("#ele").children().length>0; // if has children return true

sabrinaluo

<div>
  <p>123</p>
  <p>321</p>
  <p>456</p>
  <p>789</p>
</div>

<script>
  $("div p:first-child") //return <p>123</p>
</script>

sabrinaluo

{{#each data}}
<div>{{@index}}</div> <!-- start from 0-->
<div>{{this}}</div> <!-- "aa"-->
{{/each}}

<script>
  var data = ["aa","bb"]
</script>

sabrinaluo

language: node_js
node_js:
- '4.0'
branches:
  only:
  - master
before_install:
- openssl aes-256-cbc -K $encrypted_e011a6d7eebf_key -iv $encrypted_e011a6d7eebf_iv -in .travis/id_rsa.enc -out ~/.ssh/id_rsa -d
- chmod 600 ~/.ssh/id_rsa
- eval $(ssh-agent)

sabrinaluo

function isEmpty(obj) {
  for (var prop in obj) {
    if (obj.hasOwnProperty(prop)) {
      return false;
    }
  }
  return true;
}