tpowell/isodd.html

## isodd.html
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Odd Check!</title>
<style>
	.errMsg {color: red; font-style: italic;}

	output {background-color: orange;
		  	 width: 40%; text-align: center;
			 font-size: large; font-weight: bold;
			 display: block;
			 margin-top: 20px;
	}

	garbage {
		color: green;
		background: yellow;
		display: block;
	}
</style>
</head>
<body>

	<script>

		var JS1 = {};  // global wrapper object

		JS1.DEBUG = false;

		JS1.strings = [];
		JS1.strings['checkError'] =  "Integers only";
		JS1.strings['isOddError'] =  "isOdd requires numbers";
		JS1.strings['isOddTrue'] =  "Number is odd";
		JS1.strings['isOddFalse'] =  "Number is even";

		/*
		 * log - show a trace statement appropriately based upon browser support
		 *
		 *   params: msg - a string to output somehow
		 *   returns: nothing
		 *
		 *   Uses console.log or alert depending on support
		 */
		 JS1.log = function (msg) {

			if (!JS1.DEBUG) { // if no debugging just return
			  return;
			}

			if ((console) && (console.log)) {
			  console.log(msg);
			}
			else if (alert) {
			       alert(msg)
			     }
			     else {
			       throw "Can't log error messages";
			     }
		 } /* log */


		/*
		 * isOdd - returns true/false for if a passed number is odd or not
		 *
		 *  params: val  - an integer to check
		 *  returns: true if an odd number, false if not
		 *
		 *  Throws exception if sent wrong data type
		 */
		JS1.isOdd = function (val) {


			JS1.log("Entering function isOdd");

			if (typeof val != "number") {
			  throw JS1.strings['isOddError'];
			}

			JS1.log("isOdd calc = "+ ((val % 2) !== 0));

			return ((val % 2) !== 0);

		} /* isOdd */


	/*
	 * checkNumber - reads a form field, checks to make sure
	 *               values are integers, if not prints error message
	 *               Calls isOdd to figure out result
	 *
	 *  params: none
	 *  returns: none
	 *
	*/
	JS1.checkNumber = function () {

		var el;

		el = document.getElementById("numberToTest");
		var val = parseInt(el.value);

		if (isNaN(val)) {
		  document.getElementById("errorMessage").innerHTML = JS1.strings['checkError'];

		  document.getElementById("result").innerHTML = "";
		} else {
	      document.getElementById("errorMessage").innerHTML = "";

		  if (JS1.isOdd(val)) {
			  document.getElementById("result").innerHTML = JS1.strings['isOddTrue'];
		  } else {
			  document.getElementById("result").innerHTML = JS1.strings['isOddFalse'];
		  }

		}

	}

	window.onload = function () {
		document.getElementById("checkBtn").onclick = function () {
		  JS1.checkNumber();
		}
	}
	</script>

	<h1>Odd Checker</h1>
	<form action="#" method="get">
		<label for="numberToTest">Number:</label>
		<input type="text" id="numberToTest"
		       title="Enter a number" size="4">
		<span id="errorMessage" class="errMsg"></span>
		<br>
		<input type="button" id="checkBtn" value="Check">
	</form>

	<output id="result" for="numberToTest">

	</output>

</body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<meta charset="utf-8">
	<title>Odd Check!</title>
	<style>
	.errMsg {color: red; font-style: italic;}

	output {background-color: orange;
	width: 40%; text-align: center;
	font-size: large; font-weight: bold;
	display: block;
	margin-top: 20px;
	}

	garbage {
	color: green;
	background: yellow;
	display: block;
	}
	</style>
	</head>
	<body>

	<script>

	var JS1 = {}; // global wrapper object

	JS1.DEBUG = false;

	JS1.strings = [];
	JS1.strings['checkError'] = "Integers only";
	JS1.strings['isOddError'] = "isOdd requires numbers";
	JS1.strings['isOddTrue'] = "Number is odd";
	JS1.strings['isOddFalse'] = "Number is even";

	/*
	* log - show a trace statement appropriately based upon browser support
	*
	* params: msg - a string to output somehow
	* returns: nothing
	*
	* Uses console.log or alert depending on support
	*/
	JS1.log = function (msg) {

	if (!JS1.DEBUG) { // if no debugging just return
	return;
	}

	if ((console) && (console.log)) {
	console.log(msg);
	}
	else if (alert) {
	alert(msg)
	}
	else {
	throw "Can't log error messages";
	}
	} /* log */



	/*
	* isOdd - returns true/false for if a passed number is odd or not
	*
	* params: val - an integer to check
	* returns: true if an odd number, false if not
	*
	* Throws exception if sent wrong data type
	*/
	JS1.isOdd = function (val) {


	JS1.log("Entering function isOdd");

	if (typeof val != "number") {
	throw JS1.strings['isOddError'];
	}

	JS1.log("isOdd calc = "+ ((val % 2) !== 0));

	return ((val % 2) !== 0);

	} /* isOdd */


	/*
	* checkNumber - reads a form field, checks to make sure
	* values are integers, if not prints error message
	* Calls isOdd to figure out result
	*
	* params: none
	* returns: none
	*
	*/
	JS1.checkNumber = function () {

	var el;

	el = document.getElementById("numberToTest");
	var val = parseInt(el.value);

	if (isNaN(val)) {
	document.getElementById("errorMessage").innerHTML = JS1.strings['checkError'];

	document.getElementById("result").innerHTML = "";
	} else {
	document.getElementById("errorMessage").innerHTML = "";

	if (JS1.isOdd(val)) {
	document.getElementById("result").innerHTML = JS1.strings['isOddTrue'];
	} else {
	document.getElementById("result").innerHTML = JS1.strings['isOddFalse'];
	}

	}

	}

	window.onload = function () {
	document.getElementById("checkBtn").onclick = function () {
	JS1.checkNumber();
	}
	}
	</script>

	<h1>Odd Checker</h1>
	<form action="#" method="get">
	<label for="numberToTest">Number:</label>
	<input type="text" id="numberToTest"
	title="Enter a number" size="4">
	<span id="errorMessage" class="errMsg"></span>
	<br>
	<input type="button" id="checkBtn" value="Check">
	</form>

	<output id="result" for="numberToTest">

	</output>

	</body>
	</html>