How to iterate through functions defined in a javascript object

Question

I have an object that defines a bunch of functions like this:

myObject = {
  "item 1": function() {
    return "I'm item 1";
  },
  "item 2": function() {
    return "I'm item 2";
  }
};

I want to write a function that calls all of the functions defined in this object without having to know the names of the functions or the number of functions. Is this possible?

Theoretically, you could do `for(var f in myObject){myObject[f]();}`. But the return value will be lost. What do you want to do with the return values? — Sebastian Simon, Aug 01 '15 at 00:35

score 1 · Answer 1 · answered Aug 01 '15 at 00:46

1

In ECMAScript >=5.1 you can use the for .. in construct.

obj = {
    test : function() {
        console.log("test called");
    }
};

for(idx in obj) {
    obj[idx]();
}

You may want to check that the property is actually a function.

answered Aug 01 '15 at 00:46

reker-

26
3

score 0 · Accepted Answer · answered Aug 01 '15 at 00:36

0

You can do this by first using a for-in loop to go through each of the objects properties. Then, after checking if the value is a function, you can call it.

for (var key in obj) {
  if (typeof obj[key] === 'function') {
    obj[key]();
  }
}

answered Aug 01 '15 at 00:36

Mike Cluck

31,869
13
80
91

score 0 · Answer 3 · edited May 23 '17 at 12:29

You could either use Object.keys or a for-in loop depending on your needs.

Object.keys(obj); // ==> ["item-1", "item-2"]
Object.keys(obj).forEach(function (key) {
    var fn = obj[key];
    fn();
});

// or with a for-in loop

for (var key in obj) {
    if (obj.hasOwnProperty(key)) {
        obj[key]();
    }
}

Using Object.keys is arguably a bit more clear, but the for-in loop has better browser compatibility and possibly performance. For a more general comparison of object enumeration in JavaScript, refer to this question How do I enumerate the properties of a JavaScript object?.

How to iterate through functions defined in a javascript object

3 Answers3