Question

This question already has answers here:

how do I compare 2 functions in javascript (6 answers)

Closed 6 years ago.

如何比较 j文中两个静态功能是否平等?

Answer 1

String(f1) === String(f2)

Answer 2

var f1 = f2 = function( a ){ return a; };

在此,您可使用<代码>f1 == f2 <>/code>,因为它们重新标明同样的记忆,并重述同一类型。

var f1 = function( a ){ return a; },
    f2 = function( a ){ return a; };

您可在此使用所使用之星号(即暗中将功能转换成体体正文为“强权”)。

+f1 = +f2。

这是ence后发生的事情:

f1.toString( ) == f2.toString( )

www.un.org/Depts/DGACM/index_spanish.htm Edit:在一年之后回顾这一职位,我同意“@kangax”,你可能永远不会这样做。

Answer 3

每当我需要比较职能时我确信,没有范围模糊,使用同样的功能目标。

Saye 我有一部分图书馆职能,这些职能作为参数之一。为这一例子,<代码>create1分钟Callback功能将设定1分钟的计时器,并按每一计打回。 <密码>1分钟Callback> 后退,你必须像你那样通过<代码>create1分钟Callback。

function create1minuteCallback(callback){
//implementation
}

function kill1minuteCallback(callback){
//implementation
}

很显然,这不会奏效,因为我们正在通过的职能在第二行有所不同:

create1minuteCallback(function(){alert("1 minute callback is called");});
kill1minuteCallback(function(){alert("1 minute callback is called");});

我通常这样做:

function callbackFunc(){alert("1 minute callback is called");}

create1minuteCallback(callbackFunc);
kill1minuteCallback(callbackFunc);

Answer 4

Well, as simply as that - if you are going to compare functions, you do it for a reason I assume. What is your reason? My reason was to not run a certain function twice. I did it this way (just snippet code to get the idea)

   var x = function(){
    console.error("i am a functionX");
  }
   var y = function(){
        console.error("i am a functionX");



  }

    var z = function(){
       console.error("i am a functionZ");



  }
       var x2= x;

   var obj = new Object();
    obj[x] = "";
    obj[x2] = "";
    obj[y] = "";
    obj[z] = "";
    obj.abc = "xaxa";
                for (prop in obj) {
                    if (obj.hasOwnProperty(prop)) {
                      console.error(obj[prop] + " hello " + prop);
                    }
            }

Function x and y are the same, even though they have different whitespaces. x and y are not the same as z, since z has a different console.error. Btw open your firebug console to see it in the jsbin example

友情链接