Robot.js

function Robot() {

	var response;

	function initialHi( inputString ) {
		return ( inputString == "hi" || inputString == "hi." || inputString == "hi!" );
	};

	this.respond = function( inputString ) {
		
		var stringLowerCased = inputString.toLowerCase();

		if ( initialHi( stringLowerCased ) ) {
			response = cases[" hi"];
		} else {
			for (var key in cases) {
		        if (stringLowerCased.indexOf(key) >= 0) {
		            response = cases[key];
		            return;
		        } else {
					var ran = Math.floor( (Math.random() * ( cases.randRes.length + 1 ) ) );
					if (ran < cases.randRes.length) {
						response = cases.randRes[ran];
					} else {
						response = inputString;
					}
		      	}
		    }
		}
	};

	this.getResponse = function() {
		return response;
	};

}