function introduce() {
   alert("Hello, I am Laruence\r\n");
}

var name = "I am Laruence";
function introduce() {
   alert(this.name);
}
alert(window.introduce);
/**
* output:
* function introduce() {
* alert(this.name);
* }
*/

<input id="name" type="text" name="name" value="Laruence" />

function showValue() {
   alert(this.value);
}
document.getElementById('name').onclick = showValue;

function showValue() {
   alert(this.value);
}
document.getElementById('name').onclick = showValue;
alert(document.getElementById('name').onclick);
/**
* output
* function showValue() {
* alert(this.value);
* }
*/

function showValue() {
   alert(this.value);
}
<input id="name" type="text" name="name" value="Laruence" onclick="showValue()"/>

dom.onclick = showvalue; //没有调用符

onclick = "showvalue()" //有调用符

alert(dom.onclick);
/**
* output:
* function onclick() {
*  showValue();
* }
*/

<img src="xxx" onerror="alert(1);} function hi() { alert(2); " />

dom.onclick = showValue();
dom.onclick = function() { alert(this.value) ;}
<input onclick="alert(this.value);" /> //想想刚才我们的引用,是如何把这句嵌入的.
dom.addEventListener(dom, showValue, false); //ff only

var laruence = {
   name : 'laruence',
   age : 26,
   position : 'Senior PHP Engineer',
   company : 'Baidu.inc'
};
 
function introduce() {
   alert(this.name);
}
 
introduce.call(laruence);

var myObject = {
  sayHello : function() {
    console.log('Hi! My name is ' + this.myName);
  },

  myName : 'Rebecca'
};

var secondObject = {
  myName : 'Colin'
};

myObject.sayHello();         // logs 'Hi! My name is Rebecca'
myObject.sayHello.call(secondObject); // logs 'Hi! My name is Colin'

var myName = 'the global object',

  sayHello = function () {
    console.log('Hi! My name is ' + this.myName);
  },

  myObject = {
    myName : 'Rebecca'
  };

var myObjectHello = sayHello.bind(myObject);

sayHello();    // logs 'Hi! My name is the global object'
myObjectHello(); // logs 'Hi! My name is Rebecca'

var myName = 'the global object',

  sayHello = function() {
    console.log('Hi! My name is ' + this.myName);
  },

  myObject = {
    myName : 'Rebecca'
  },

  secondObject = {
    myName : 'Colin'
  };

myObject.sayHello = sayHello;
secondObject.sayHello = sayHello;

sayHello();        // logs 'Hi! My name is the global object'
myObject.sayHello();   // logs 'Hi! My name is Rebecca'
secondObject.sayHello(); // logs 'Hi! My name is Colin'

var myNamespace = {
  myObject : {
    sayHello : function() {
      console.log('Hi! My name is ' + this.myName);
    },

    myName : 'Rebecca'
  }
};

var hello = myNamespace.myObject.sayHello;

hello(); // logs 'Hi! My name is undefined'

var myNamespace = {
  myObject : {
    sayHello : function() {
      console.log('Hi! My name is ' + this.myName);
    },

    myName : 'Rebecca'
  }
};

var obj = myNamespace.myObject;

obj.sayHello(); // logs 'Hi! My name is Rebecca'