I'm pushing some anonymous functions into an array this way:
myArray.push(function(){ /* some cool code here */});
myArray.push(function(){ /* some cooler code here */});
Then I execute all functions doing
while (myArray.length) { myArray.shift().call();}
The question is: how can I check if a function is already into myArray? I Tried to do a comparison using toSource() but it does not work... Any idea?
Thanks in advance.
Do your comparison of the functions as a string:
func1.toString() === func2.toString()
This will even work with anonymous functions, but assumes that by equivalent you mean having the same code, character for character.
You can use Array.prototype.indexOf to check whether your array has that function or not:
var foo = function () {};
var bar = function () {};
var arr = [];
var addFunction = function (f) {
if (arr.indexOf(fn) === -1) {
arr.push(fn);
}
};
addFunction(foo);
addFunction(foo);
console.log(arr.indexOf(foo)); // prints 0
console.log(arr.indexOf(bar)); // prints -1
You can also create a map to check whether you added this function or not:
var foo = function foo() {};
var bar = function bar() {};
var arr = [];
var map = {};
var addFunction (fn) {
if (!map[fn.name]) {
arr.push(fn);
map[fn.name] = fn;
}
};
addFunction(foo);
addFunction(foo);
console.log(arr.indexOf(foo), map['foo']); // prints 0, function foo() { ... }
console.log(arr.indexOf(bar), map['bar']); // prints -1, undefined
Note: This second example might not work with anonymous functions.
As you're adding functions to the list, keep a separate object in which you record some sort of identifier that allows you to check whether the function has been added to the array:
var myArray = [], addedFunctions = {};
for (var i = 0; i < whatever; ++i) {
// do whatever
if (something) {
if (!addedFunctions[ "cool code 1" ]) {
myArray.push(function() { /* cool code 1 */ });
addedFunctions[ "cool code 1" ] = true;
}
}
if (somethingElse) {
if (!addedFunctions[ "cool code 2" ]) {
myArray.push(function() { /* cool code 2 */ });
addedFunctions[ "cool code 2" ] = true;
}
}
}
myArray.