toString function for an object with key:value pairs.

ObjectToString.js

function objectToString(obj){
	var result = [];
	result.push('{ ');
	for (var key in obj){
		if (result.length > 1){
			result.push(', ');
		}
		
		result.push(key+' : ');
		var value;
		if (typeof obj[key] === 'undefined'){
			value = 'undefined';
		} else if (obj[key] === null){
			value = 'null';
		} else if (typeof obj[key] === 'string' || obj[key] instanceof String ){ 
			value = '"'+obj[key]+'"';
		} else if (obj[key] instanceof Object){
			value = objectToString(obj[key]);
		} else {
			value = obj[key];
		}
		
		result.push(value);
	}
	result.push(' }');
	return result.join('');
};

Aaaand, as it usually turns out, this is already implemented in vanilla JavaScript via the JSON.stringify method. Oh well. If anyone's interested in the sauce for that, it's on Douglas Crockford's GitHub.