dschnare · September 29, 2011 15:31
diff --git a/equals.js b/equals.js
 // Author: Darren Schnare
 // Keywords: javascript,equality,testing,equals,object
 // License: MIT ( http://www.opensource.org/licenses/mit-license.php )
 // Repo: https://gist.github.com/1251001

 // Creates an equals function within the specified scope.
 (function(scope) {
    // Determines if two objects have the same values. This is a
    // recursive test that tests all objects through out the object
    // tree.
    //
    // This function uses the built-in valueOf() functionality of
    // all JavaScrpt objects to convert a and b to native objects.
    // You can use this to your advantage when wanting to compare
    // complex objects.
    //
    // equals(a, b)
    scope.equals = function equals(a, b) {
        var typeofa, typeofb, i, len, key;

        // If a and b refer to the same object then they are equal.
        if (a === b) return true;

        // Get the native type of both a and b. Use the built-in valueOf()
        // function to get the native object of each variable.
        typeofa = a === null ? "null" : typeof (a = a ? a.valueOf() : a);
        typeofb = b === null ? "null" : typeof (b = b ? b.valueOf() : b);

        // If a and b are not the same native type.
        if (typeofa !== typeofb) return false;

        switch (typeofa) {
            case "string":
            case "boolean":
            case "number":
            case "functon":
            case "undefined":
            case "null":
                return a === b;
        }

        // Convert the native type to a string. This allows us to test
        // if either a or b are Arrays and then handle accordingly.
        typeofa = ({}).toString.call(a);
        typeofb = ({}).toString.call(b);

        if (typeofa === typeofb) {
            // Compare the items of two arrays
            if (typeofa === "[object Array]") {
                if (a.length !== b.length) return false;

                len = a.length;
                for (i = 0; i < len; i++) {
                    if (!equals(a[i], b[i])) return false;
                }
            // Compare the keys of two objects
            } else {
                for (key in a) {
                    if (!(key in b)) return false;

                    if (!equals(a[key], b[key])) return false;
                }
            }
        } else {
            return false;
        }

        return true;
    }
 }(window));
diff --git a/fiddle.html b/fiddle.html
 <!--Author: Darren Schnare
 Keywords: javascript,equality,testing,equals,object
 License: MIT ( http://www.opensource.org/licenses/mit-license.php )
 Repo: https://gist.github.com/1251001-->
 <!DOCTYPE html>
 <html>
    <head>
        <meta charset="utf-8" />
        <title>EqualsJS Example</title>
        <script type="text/javascript" src="https://gist.github.com/raw/1251001/equals.js"></script>                
    </head>
    <body>
        <script type="text/javascript">                       
            // Handle logging messages.
            function log(/*...*/) {
                var doc = document, body = doc.getElementsByTagName("body")[0];
                for (var i = 0, len = arguments.length; i < len; i++) {
                    body.appendChild(doc.createTextNode(arguments[i] + ""));
                    body.appendChild(doc.createElement("br"));
                }
            }

            
            var a = [1,2,3];
            var b = [1,2,3];
            log(equals(a, b)); // true

            a.pop();
            log(equals(a, b)); // false

            b.pop();
            a.push({name: "John"});
            b.push({name: "Dave"});
            log(equals(a, b)); // false

            b[b.length - 1].name = "John";
            log(equals(a, b)); // true



            a.push(4,5,6,7,8,9);
            a.valueOf = function() {
                return "a";
            }
            log(equals(a, b)); // false

            // Give be the same valueOf() as a.
            // Now a is equal to b.
            b.valueOf = function() {
                return "a";
            }
            log(equals(a, b)); // true            
        </script>
    </body>
 </html>
diff --git a/fiddle.manifest b/fiddle.manifest
 name: EqualsJS - Deep equality testing.
 description: Performs recursive equality testing on two objects.
 authors:
  - Darren Schnare
	// Author: Darren Schnare
	// Keywords: javascript,equality,testing,equals,object
	// License: MIT ( http://www.opensource.org/licenses/mit-license.php )
	// Repo: https://gist.github.com/1251001

	// Creates an equals function within the specified scope.
	(function(scope) {
	// Determines if two objects have the same values. This is a
	// recursive test that tests all objects through out the object
	// tree.
	//
	// This function uses the built-in valueOf() functionality of
	// all JavaScrpt objects to convert a and b to native objects.
	// You can use this to your advantage when wanting to compare
	// complex objects.
	//
	// equals(a, b)
	scope.equals = function equals(a, b) {
	var typeofa, typeofb, i, len, key;

	// If a and b refer to the same object then they are equal.
	if (a === b) return true;

	// Get the native type of both a and b. Use the built-in valueOf()
	// function to get the native object of each variable.
	typeofa = a === null ? "null" : typeof (a = a ? a.valueOf() : a);
	typeofb = b === null ? "null" : typeof (b = b ? b.valueOf() : b);

	// If a and b are not the same native type.
	if (typeofa !== typeofb) return false;

	switch (typeofa) {
	case "string":
	case "boolean":
	case "number":
	case "functon":
	case "undefined":
	case "null":
	return a === b;
	}

	// Convert the native type to a string. This allows us to test
	// if either a or b are Arrays and then handle accordingly.
	typeofa = ({}).toString.call(a);
	typeofb = ({}).toString.call(b);

	if (typeofa === typeofb) {
	// Compare the items of two arrays
	if (typeofa === "[object Array]") {
	if (a.length !== b.length) return false;

	len = a.length;
	for (i = 0; i < len; i++) {
	if (!equals(a[i], b[i])) return false;
	}
	// Compare the keys of two objects
	} else {
	for (key in a) {
	if (!(key in b)) return false;

	if (!equals(a[key], b[key])) return false;
	}
	}
	} else {
	return false;
	}

	return true;
	}
	}(window));
	<!--Author: Darren Schnare
	Keywords: javascript,equality,testing,equals,object
	License: MIT ( http://www.opensource.org/licenses/mit-license.php )
	Repo: https://gist.github.com/1251001-->
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8" />
	<title>EqualsJS Example</title>
	<script type="text/javascript" src="https://gist.github.com/raw/1251001/equals.js"></script>
	</head>
	<body>
	<script type="text/javascript">
	// Handle logging messages.
	function log(/.../) {
	var doc = document, body = doc.getElementsByTagName("body")[0];
	for (var i = 0, len = arguments.length; i < len; i++) {
	body.appendChild(doc.createTextNode(arguments[i] + ""));
	body.appendChild(doc.createElement("br"));
	}
	}


	var a = [1,2,3];
	var b = [1,2,3];
	log(equals(a, b)); // true

	a.pop();
	log(equals(a, b)); // false

	b.pop();
	a.push({name: "John"});
	b.push({name: "Dave"});
	log(equals(a, b)); // false

	b[b.length - 1].name = "John";
	log(equals(a, b)); // true



	a.push(4,5,6,7,8,9);
	a.valueOf = function() {
	return "a";
	}
	log(equals(a, b)); // false

	// Give be the same valueOf() as a.
	// Now a is equal to b.
	b.valueOf = function() {
	return "a";
	}
	log(equals(a, b)); // true
	</script>
	</body>
	</html>
	name: EqualsJS - Deep equality testing.
	description: Performs recursive equality testing on two objects.
	authors:
	- Darren Schnare