Guessing game

SUBMITTED BY: FatCookies

DATE: Sept. 9, 2016, 2:22 a.m.

FORMAT: Text only

SIZE: 4.2 kB

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  1. /*
  2. "guessing.js" is a simple guessing game written to introduce students to
  3. the basics of game programming. Written by David Johnston in 2016 whilst
  4. employed by the NSW Department of Education.
  5. */
  7. // game constants -------------------------------------------------------------
  9. const TITLE = "Guessing Game";
  10. const MAXNUM = 20;
  11. const CLUELOWER = "It's lower than that.";
  12. const CLUEHIGHER = "It's higher than that.";
  13. const REPSUCCESS = "Yes! You got it!";
  14. const REPINIT = "Guess the correct number before your score reaches zero!";
  15. const NAIREPLY = "That doesn't appear to be an integer. Try again.";
  17. // insults at: [http://goo.gl/AH99cv] datahamster.com/autoinsult/
  19. const R00 = "Ha! Ha! You're wrong!";
  20. const R01 = "Nope! Try again.";
  21. const R02 = "Sigh. You're not very good at this.";
  23. const ENTERKEY = 13; // the keycode for the enter key
  25. // game variables -------------------------------------------------------------
  27. var theNumber = Math.floor(Math.random() * MAXNUM);
  28. var guess = "0"; // will be *string* entered by player
  29. var score = MAXNUM; //score counts down from this number
  30. var replies = [R00, R01, R02];
  31. var repliesIndex = 0;
  32. var comment = "This will be changed later in the code.";
  33. var gameIsOver = false;
  35. // get and setup the page title -----------------------------------------------
  37. var pageTitle = document.getElementById("pageTitle");
  38. pageTitle.innerHTML = TITLE;
  40. var headingArea = document.getElementById("headingArea");
  41. headingArea.innerHTML = TITLE;
  43. // get and setup (if needed) the other page elements --------------------------
  45. var scoreArea = document.getElementById("scoreArea");
  46. scoreArea.innerHTML = "Score: " + MAXNUM;
  48. var instructionArea = document.getElementById("instructionArea");
  49. instructionArea.innerHTML = "Guess an integer between 0 and " + MAXNUM + ".";
  51. var playArea = document.getElementById("playArea");
  53. var commentArea = document.getElementById("commentArea");
  54. commentArea.innerHTML = REPINIT;
  56. var guessField = document.getElementById("guessField");
  57. var guessLength = ((MAXNUM.toString()).length).toString();
  58. guessField.setAttribute("maxlength", guessLength);
  59. guessField.setAttribute("size", guessLength);
  61. var guessButton = document.getElementById("guessButton");
  62. guessButton.setAttribute("onclick","checkGuess()");
  64. var resetButton = document.getElementById("resetButton");
  65. resetButton.setAttribute("onclick","location.reload()");
  67. // listen for the enter key ---------------------------------------------------
  69. document.onkeyup = checkLift;
  70. function checkLift(e)
  71. {
  72. if (e.keyCode === ENTERKEY)
  73. checkGuess();
  74. }
  76. // give the guess field the focus ---------------------------------------------
  78. window.onload = selectGuessField;
  79. function selectGuessField()
  80. {
  81. guessField.select();
  82. guessField.focus();
  83. }
  85. // the game "loop" ------------------------------------------------------------
  87. function checkGuess()
  88. {
  89. // ***** get inputs *****
  91. guess = parseFloat(guessField.value);
  93. // ***** calculate new state *****
  95. if (Number.isInteger(guess)) // an integer was entered
  96. {
  97. if (guess == theNumber) // the guess was correct (collision detection)
  98. {
  99. comment = REPSUCCESS;
  100. gameIsOver = true;
  101. }
  102. else // the guess was incorrect
  103. {
  104. repliesIndex = Math.floor(Math.random() * replies.length);
  105. score = score - 1;
  107. if (guess > theNumber) // the guess is too large
  108. {
  109. comment = replies[repliesIndex] + " " + CLUELOWER;
  110. }
  111. else // the guess must be too small (equality is already handled)
  112. {
  113. comment = replies[repliesIndex] + " " + CLUEHIGHER;
  114. }
  115. }
  116. }
  117. else // an integer was not entered
  118. {
  119. comment = NAIREPLY;
  120. }
  122. // ***** render new state *****
  124. commentArea.innerHTML = comment;
  125. scoreArea.innerHTML = "Score: " + score;
  127. if (gameIsOver)
  128. {
  129. playArea.innerHTML = "▶ ▶ ▶  "
  130. + guess + "  ◀ ◀ ◀";
  131. }
  132. else
  133. {
  134. selectGuessField();
  135. }
  136. }
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