调用JS变量内的值作为JS函数名称

Question

Hello I have a function to perform actions but name of the function is inside a variable...

below code will get the URL's hashed part example: #JHON and remove # and store it inside URLHASH variable..example: JHON

  var urlhash = document.location.hash;
  urlhash = urlhash.replace(/^.*#/, '');

always there is a function name from that value inside variable and i want to call value inside that variable as a function name

  window.onload=function() {
    Value inside URLHASH variable should run as a name of a variable. example: jhon();
  };

Is it possible ? I tried some codes but it calls variable name as a function not value inside the variable..help me..

Answer 1

You can use the following:

window[urlhash]();

This will invoke a function whose name is the value of the urlhash variable, defined in the context of window . Here's a DEMO .

Answer 2

You can access attributes of objects as if they are array indexes, so for example, you could run getElementById this way:

document["getElementById"]("#myid");

so& if you know beforehand of which object the function will be a member, you can access it this way. functions in the global scope are methods of the window object. However, if the hash may contain expressions like #document.write() , you would have to do some parsing. it could work like this

window.onload=function() {
    var urlhash = document.location.hash, current_element = window;
    urlhash = urlhash.replace(/^.*#/, '');
    elements = urlhash.split(".");
    for(var i=0; i<elements.length; i++){
        current_element = current_element[elements[i]];
    }
    //execute the actual function
    current_element();
};