javascript

console.log("Hello world!");

定义一个类

格式类似于定义一个函数：

var Person = function() {
    // property
    this.name = "Zhongwei";
    this.age = 28;
   
    // method 
    this.start_running = function() {
        alert("running...");
    }
}

使用

var zhongwei = new Person();
console.log(zhongwei.name);
zhongwei.start_running();

宿主对象

浏览器提供了两个对象:

• window 对象 -> BOM (Browser Object Model)
• document 对象 -> DOM (Document Object Model)

window 对象用于控制浏览器窗口，获取浏览器窗口属性，例如窗口大小。

document 对象用于获取和控制网页内容。

var title = document.getElementById("title");

javascript 中使用 sleep

javascript 中没有 sleep 这个函数，但是可以使用

setTimeout(some_function(), 3000);

即，3秒后调用 some_function 这个函数。

http://stackoverflow.com/questions/1141302/is-there-a-sleep-function-in-javascript

确认 json 里某个 key 是否存在

    if(json_object.hasOwnProperty('name')){
        //do struff
    }

email 地址格式验证

  function validate_email(email) {
    var re = /^(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$/;
    return re.test(email);
  }

域名格式验证

  function validate_hostname_or_ip(hostname) {
    if (hostname.indexOf(".") === -1) {
      return false
    }
    // http://stackoverflow.com/questions/9208814/validate-ipv4-ipv6-and-hostname
    var expression = /((^\s*((([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5]))\s*$)|(^\s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:)))(%.+)?\s*$))|(^\s*((?=.{1,255}$)(?=.*[A-Za-z].*)[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b-){0,61}[0-9A-Za-z])?(?:\.[0-9A-Za-z](?:(?:[0-9A-Za-z]|\b-){0,61}[0-9A-Za-z])?)*)\s*$)/;
    return expression.test(hostname);
  }

防止联系提交两次

按下按钮之后，应防止一次返回之前，又点击了一次。

遍历

遍历数组

var myStringArray = ["Hello","World"];
for (var i = 0; i < myStringArray.length; i++) {
    alert(myStringArray[i]);
    //Do something
}

遍历对象属性

var obj = {
  "a": 1,
  "b": 2,
  "c": 3
};

for (var prop in obj) {
  if (obj.hasOwnProperty(prop)) { 
  // or if (Object.prototype.hasOwnProperty.call(obj,prop)) for safety...
    alert("prop: " + prop + " value: " + obj[prop])
  }
}

参考：

• http://stackoverflow.com/questions/3010840/loop-through-array-in-javascript