.NET-style String.Format implementation for JavaScript

StringUtils.js

/*global JSON */

if ("undefined" === typeof String.format) {

	// String.format: populates a format string with an ordered list of values
	/*string*/ String.format = function(/*params*/) {
		var args = arguments,
			num = args.length,
			str = args[0];

		if (!num || !str) {
			return str||"";
		}

		for (var i=1; i<num; i++) {
			var value = args[i];
			if (typeof value === "object") {
				value = JSON.stringify(value);
			}

			str = str.replace(new RegExp("\\{" + (i-1) + "\\}", "g"), String(value));
		}

		return str;
	};
}

if ("undefined" === typeof String.formatKeys) {

	// String.formatKeys: populates a format string with a dictionary
	/*string*/ String.formatKeys = function(/*string*/ str, /*object*/ values) {
		if (!str || !values || typeof values !== "object") {
			return str||"";
		}

		for (var key in values) {
			if (key && values.hasOwnProperty(key)) {
				var value = values[key];
				if (typeof value === "object") {
					value = JSON.stringify(value);
				}
				str = str.replace(new RegExp("\\{" + key + "\\}", "gi"), String(value));
			}
		}
		return str;
	};
}

if ("undefined" === typeof String.prototype.trim) {
	/*string*/ String.prototype.trim = function () {
		return this.replace(/^\s*|\s*$/g, "");
	};
}