CSC 107 Fall 2002
C. JavaScript Libraries
[ random.js |
prompt.js |
verify.js |
char.js |
array.js ]
<![CDATA[
// File: random.js
// Author: Dave Reed
// Date: 7/10/02
//
// This file contains several routines for generating random values
////////////////////////////////////////////////////////////////////////
function RandomNum(low, high)
// Given : low <= high
// Returns : a random number in the range [low, high)
{
return Math.random()*(high-low) + low;
}
function RandomInt(low, high)
// Given : low <= high
// Returns : a random integer in the range [low, high]
{
return Math.floor(Math.random()*(high-low+1)) + low;
}
function RandomChar(str)
// Given : str is a nonempty string
// Returns: a random character from the string
{
return str.charAt(RandomInt(0, str.length-1));
}
function RandomOneOf(list)
// Given : list is a nonempty list (array)
// Returns: a random item from the list
{
return list[RandomInt(0, list.length-1)];
}
]]>
<![CDATA[
// File: verify.js
// Author: Dave Reed
// Date: 7/10/02
//
// This library contains functions for verifying the contents of
// a text box. For each function the name of a text box is passed
// as input, along with any restrictions on the contents. If the
// contents of the box are not legal, a warning is displayed.
/////////////////////////////////////////////////////////////////////
function VerifyNum(textBox, resetValue)
// Assumes: textBox is a text box in the page
// Results: alert if textBox does not contain a number & clears contents
{
var boxValue;
boxValue = parseFloat(textBox.value);
if ( isNaN(boxValue) ) {
alert("You must enter a number value!");
textBox.value = "";
}
}
function VerifyNumInRange(textBox, low, high, resetValue)
// Assumes: textBox is a text box in the page
// Results: alert if textBox does not contain an integer & clears contents
{
var boxValue;
boxValue = parseFloat(textBox.value);
if ( isNaN(boxValue) || (boxValue < low) || (boxValue > high)) {
alert("You must enter a number value in the range [" +
low + ".." + high + "]");
textBox.value = "";
}
}
function VerifyInt(textBox)
// Assumes: textBox is a text box, low <= high, resetValue is optional
// Results: alert if textBox does not contain a number in range & clears
{
var boxValue;
boxValue = parseFloat(textBox.value);
if ( isNaN(boxValue) || (boxValue % 1 != 0) ) {
alert("You must enter an integer value!");
textBox.value = "";
}
}
function VerifyIntInRange(textBox, low, high)
// Assumes: textBox is a text box, low <= high
// Results: alert if textBox does not contain an integer in range & clears
{
var boxValue;
boxValue = parseFloat(textBox.value);
if ( isNaN(boxValue) || (boxValue % 1 != 0) ||
(boxValue < low) || (boxValue > high)) {
alert("You must enter an integer value in the range [" + low + ".." + high + "]");
textBox.value = "";
}
}
function VerifyOneOf(textBox, options)
// Assumes: textBox is a text box, options is a list, resetValue is optional
// Results: alert if textBox does not contain one of options & clears
{
var i;
for (i = 0; i < options.length; i++) {
if (textBox.value == options[i]) {
return;
}
}
alert("You must enter one of the following: " + options);
textBox.value = "";
}
]]>
<![CDATA[
// File: prompt.js
// Author: Dave Reed
// Date: 7/10/02
//
// This file contains several routines for prompting and reading values
////////////////////////////////////////////////////////////////////////
function PromptNum(message)
// Given : message is a string
// Returns: number value read in from user (using prompt message)
{
var value, parsed;
value = prompt(message, "");
while (true) {
if (value == null) {
return null;
}
parsed = parseFloat(value);
if (!isNaN(parsed)) {
return parsed;
}
value = prompt(message, "A NUMBER");
}
}
function PromptNumInRange(message, low, high)
// Given : message is a string, low < high
// Returns: value read in from user in range [low, high)
{
var value, parsed;
value = prompt(message, "");
while (true) {
if (value == null) {
return null;
}
parsed = parseFloat(value);
if (!isNaN(parsed) && low <= parsed && parsed < high) {
return parsed;
}
value = prompt(message, low + " <= NUMBER < " + high);
}
}
function PromptInt(message)
// Given : message is a string
// Returns: integer value read in from user (using prompt message)
{
var value, parsed;
value = prompt(message, "");
while (true) {
if (value == null) {
return null;
}
parsed = parseFloat(value);
if (!isNaN(parsed) && (parsed % 1 == 0)) {
return parsed;
}
value = prompt(message, "AN INTEGER");
}
}
function PromptIntInRange(message, low, high)
// Given : message is a string, low <= high (both integers)
// Returns: integer value read in from user in range [low,high]
{
var value, parsed;
value = prompt(message, "");
while (true) {
if (value == null) {
return null;
}
parsed = parseFloat(value);
if (!isNaN(parsed) && (parsed % 1 == 0) && low <= parsed && parsed <= high) {
return parsed;
}
value = prompt(message, low + " <= INTEGER <= " + high);
}
}
function PromptOneOf(message, options)
// Given : message is a string, options is a nonempty array
// Returns: item read in from user contained in the options array
{
var value, i;
value = prompt(message, "");
while (true) {
if (value == null) {
return null;
}
for (i = 0; i < options.length; i++) {
if ((typeof(options[i]) == "number" && parseFloat(value) == options[i]) ||
(value == options[i])) {
return options[i];
}
}
value = prompt(message, options.join(" OR "));
}
}
]]>
<![CDATA[
// File: char.js
// Author: Dave Reed
// Date: 7/10/02
//
// This file contains several routines for recognizing characters.
////////////////////////////////////////////////////////////////////////
function IsLower(ch)
// Given : ch is a character
// Returns : true if ch is a lower-case letter
{
var lowers;
lowers = "abcdefghijklmnopqrstuvwxyz";
return (lowers.indexOf(ch) != -1);
}
function IsUpper(ch)
// Given : ch is a character
// Returns : true if ch is a upper-case letter
{
var uppers;
uppers = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
return (uppers.indexOf(ch) != -1);
}
function IsLetter(ch)
// Given : ch is a character
// Returns : true if ch is a letter
{
return (IsUpper(ch) || IsLower(ch));
}
function IsVowel(ch)
// Given : ch is a character
// Returns : true if ch is a vowel
{
var vowels;
vowels = "aeiouAEIOU";
return (vowels.indexOf(ch) != -1);
}
function IsConsonant(ch)
// Given : ch is a character
// Returns : true if ch is a consonant
{
return (IsLetter(ch) && !IsVowel(ch));
}
function IsDigit(ch)
// Given : ch is a character
// Returns : true if ch is a digit
{
var digits;
digits = "0123456789";
return (digits.indexOf(ch.toLowerCase()) != -1);
}
function IsWhitespace(ch)
// Given : ch is a character
// Returns : true if ch is whitespace
{
var white;
white = " \t\n\r";
return (white.indexOf(ch.toLowerCase()) != -1);
}
]]>
<![CDATA[
// File: array.js
// Author: Dave Reed
// Date: 7/10/02
//
// This file contains a routine for converting a string to an array.
////////////////////////////////////////////////////////////////////////
function IsWhite(ch)
// Given : ch is a character
// Returns : true if ch is a whitecase letter
{
var white;
white = " \t\n\r";
return (white.indexOf(ch) != -1);
}
function StringToArray(str)
// Assumes: str is a sequence of words, separated by whitespace
// Returns: an array containing the individual words
{
var items, count, index;
items = [];
count = 0;
while (str != "") {
index = 0;
while (index < str.length && IsWhite(str.charAt(index))) {
index++;
}
if (index < str.length) {
var item = "";
while (index < str.length && !IsWhite(str.charAt(index))) {
item += str.charAt(index);
index++;
}
items[count] = item
count++;
}
str = str.substring(index+1, str.length);
}
return items;
}
function ParseArray(strArray)
// Assumes: strArray is an array of strings repr. numbers
// Returns: a copy of array with elements converted to numbers
{
var index;
index = 0;
while (index < strArray.length) {
strArray[index] = parseFloat(strArray[index]);
index = index + 1;
}
return strArray;
}
]]>