How to turn a String into a JavaScript function call?

This question already has an answer here:

How to execute a JavaScript function when I have its name as a string 29 answers

---

Seeing as I hate eval, and I am not alone:

var fn = window[settings.functionName];
if(typeof fn === 'function') {
    fn(t.parentNode.id);
}

Edit: In reply to @Mahan's comment: In this particular case, settings.functionName would be "clickedOnItem" . This would, at runtime translate var fn = window[settings.functionName]; into var fn = window["clickedOnItem"] , which would obtain a reference to function clickedOnItem (nodeId) {} . Once we have a reference to a function inside a variable, we can call this function by "calling the variable", ie fn(t.parentNode.id) , which equals clickedOnItem(t.parentNode.id) , which was what the OP wanted.

More full example:

/* Somewhere: */
window.settings = {
  /* [..] Other settings */
  functionName: 'clickedOnItem'
  /* , [..] More settings */
};

/* Later */
function clickedOnItem (nodeId) {
  /* Some cool event handling code here */
}

/* Even later */
var fn = window[settings.functionName]; 
/* note that settings.functionName could also be written
   as window.settings.functionName. In this case, we use the fact that window
   is the implied scope of global variables. */
if(typeof fn === 'function') {
    fn(t.parentNode.id);
}

---

window[settings.functionName](t.parentNode.id);

不需要eval（）

---

Here is a more generic way to do the same, while supporting scopes :

// Get function from string, with or without scopes (by Nicolas Gauthier)
window.getFunctionFromString = function(string)
{
    var scope = window;
    var scopeSplit = string.split('.');
    for (i = 0; i < scopeSplit.length - 1; i++)
    {
        scope = scope[scopeSplit[i]];

        if (scope == undefined) return;
    }

    return scope[scopeSplit[scopeSplit.length - 1]];
}

Hope it can help some people out.

链接地址: http://www.djcxy.com/p/94818.html

上一篇: 调用变量中命名的JavaScript函数

下一篇: 如何将字符串转换为JavaScript函数调用？