Code examples for javascript to obtain function names, function parameters, and object attribute names_Basic knowledge

1. Three implementation methods for obtaining function names

Example 1:

A method seen in the js authoritative guide:

Function.prototype.getName = function(){
return this.name || this.toString().match(/functions*([^(]*)(/)[1]
}

Example 2:

If the current function is a named function, its name is returned. If it is an anonymous function, the assigned function variable name is returned. If it is an anonymous function in a closure, "anonymous" is returned.

Copy code The code is as follows:

var getFnName = function(callee){
var _callee = callee.toString().replace(/[s?]*/g,""),
comb = _callee.length >= 50 ? 50 :_callee.length;
_callee = _callee.substring (0,comb);
var name = _callee.match(/^function([^(] ?)(/);
if(name && name[1]){
return name[1 ];
}
var caller = callee.caller,
_caller = caller.toString().replace(/[s?]*/g,"");
var last = _caller. indexOf(_callee),
str = _caller.substring(last-30,last);
name = str.match(/var([^=] ?)=/);
if(name && name[1]){
          return name[1]; Function, pass in one parameter, which is arguments.callee. function ee(){
//
var fnname =getFnName(arguments.callee)
//
alert(fnname)

};
ee();

Example 3:

Copy code


The code is as follows:


function getFuncName(_callee)

{ var _text = _callee.toString();

var _scriptArr = document.scripts; for (var i=0; i<_scriptArr.length; i ) {

var _start = _scriptArr[i ].text.indexOf(_text);

if (_start != -1)

{ if (/^functions*(.*).*rn/.test(_text)) { var _tempArr = _scriptArr[i].text.substr(0, _start).split('rn'); return _tempArr[_tempArr.length - 1].replace(/(var)|(s *)/g, '').replace(/=/g, ''); } else

return _text.match(/^functions*([^(] ).*rn/ )[1];

}
}
}
function a()
{
return getFuncName(arguments.callee);
}
var b = function ()
{
return getFuncName(arguments.callee);
}
window.alert(a());
window.alert(b());




There is another situation that cannot be solved by the above method. I hope someone who has a solution can give some advice.




Copy code


The code is as follows:


var x = 
{ 

 run: function()

{

return getFuncName(arguments.callee);

}

}
window.alert(x.run()); In this case, the name of the function cannot be obtained;

2. js method to obtain all parameters of a function and traverse all attribute names and values ​​of an object 1. Get all parameters

Copy the code


The code is as follows:

function test(){

for(var i=0;i document.write(arguments[i]); }

2. Method to traverse all attribute names and values ​​of an object

Copy code Code As follows:

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