function callSomeFunction(someFunction, someArgument){      return someFunction(someArgument);    }    function add10(num){      return num + 10;    }        var result1 = callSomeFunction(add10, 10);//調用add10 把參數10傳給add10    alert(result1);  //20        function getGreeting(name){      return "Hello, " + name;    }        var result2 = callSomeFunction(getGreeting, "Nicholas");    alert(result2);  //Hello, Nicholas

function createComparisonFunction(propertyName) {          return function(object1, object2){        var value1 = object1[propertyName];        var value2 = object2[propertyName];            if (value1 < value2){          return -1;        } else if (value1 > value2){          return 1;        } else {          return 0;        }      };    }    var data = [{name: "Zachary", age: 28}, {name: "Nicholas", age: 29}];        data.sort(createComparisonFunction("name"));//sort函數接收一個函數作為排序的參考，函數createComparisonFuntion返回了一個匿名的排序函數    alert(data[0].name); //Nicholas        data.sort(createComparisonFunction("age"));    alert(data[0].name); //Zachary    

 function sum(num1, num2){      return num1 + num2;    }        function callSum1(num1, num2){      return sum.apply(this, arguments);//sum函數請求把callSum1的指針傳給自己，并作計算，此時的this指向callSum1    }        function callSum2(num1, num2){      return sum.apply(this, [num1, num2]);    }        alert(callSum1(10,10));  //20    alert(callSum2(10,10));  //20

function outer(){      inner();    }        function inner(){      alert(inner.caller);    }        outer();caller//返回一個對函數的引用，該函數調用了當前函數。

function outer(){      inner();    }    function inner(){      alert(arguments.callee.caller);      //argments.callee就是函數體本身，arguments.callee.caller就是函數體的調用函數體    }    outer();function factorial(num){      if (num <= 1) {        return 1;      } else {        return num * arguments.callee(num-1)//callee當前函數的引用即factorial函數本身的函數體      }    }    var trueFactorial = factorial;        factorial = function(){      return 0;    };        alert(trueFactorial(5));  //120    alert(factorial(5));    //0

 window.color = "red";    var o = { color: "blue" };                  function sayColor(){      alert(this.color);    }    var objectSayColor = sayColor.bind(o);    objectSayColor();  //blue    /*      bind主要是為了改變函數內部的this指向，這個是在ECMA5以后加入的，所以IE8一下的瀏覽器不支持      bind方法會創建一個新函數,稱為綁定函數.當調用這個綁定函數時,綁定函數會以創建它時傳入bind方法的第一個參數作為this,      傳入bind方法的第二個以及以后的參數加上綁定函數運行時本身的參數按照順序作為原函數的參數來調用原函數.    */

window.color = "red";    var o = { color: "blue" };        function sayColor(){      alert(this.color);    }        sayColor();      //red        sayColor.call(this);  //red 此時this指向window    sayColor.call(window); //red 同上    sayColor.call(o);   //blue 此時sayColor的指針指向o function sum(num1, num2){      return num1 + num2;    }        function callSum(num1, num2){      return sum.call(this, num1, num2);    }        alert(callSum(10,10));  //20

function sayName(name){      alert(name);    }           function sum(num1, num2){      return num1 + num2;    }        function sayHi(){      alert("hi");    }        alert(sayName.length); //1    alert(sum.length);   //2    alert(sayHi.length);  //0    //實際返回的是函數的參數的長度