Assignment 3 - Searching Algorithm

by sheila massey

HTML

<h1>Search Algorithm</h1>

Choose a number from 1 to 1000 to have the computer guess.
<input type="number" id="numGuess" min="0" max="1000" value="" />
<input type="button" class="btnstyle" value="Guess" id="btnGuess" />
 
<br />
-------------------------------------------------------------------------------------------------------------------
<br />
 
<div id="message">
</div>

-------------------------------------------------------------------------------------------------------------------
<br />
 
<div class="container" id="output">
</div>

JavaScript

var numArray = [];
var guesses = 0;
var d = "";

document.getElementById("btnGuess").onclick = function() {
  guess();
};

function guess() {
  var guessNum = document.getElementById("numGuess").value;
  var num1;
  var num2 = 500;

  clearDisplay();

 //////////////////////////////////////////////////////////////////////////////////////////////
 // Error outside of number range
 
 try {
    if (guessNum < 1 || guessNum > 1000) 
    {
      throw "ERROR! Guess should be between 1 and 1000, try agin.";
    }
    
  } catch (err) 
  	{
    document.getElementById("message").innerHTML = err;
    return;
  	}

 /////////////////////////////////////////////////////////////////////////////////////////////
 // Word output for how the computer is guessing
  
  if (guessNum > num2) {
    num1 = 1000;
  } else if (guessNum < num2) {
    num1 = 0;
  } else if (guessNum == num2) {
    document.getElementById("output").innerHTML = "Guessed " + num2 + " - Got it";
    guesses = 1;
  }

////////////////////////////////////////////////////////////////////////////////////////////////
// Declaring Midpoints

  createArray();
  var midpoint;

  do {
    midpoint = Math.round((num1 + num2) / 2);
    guesses++;

    if (guessNum < 500) {    
    
    if (midpoint < guessNum) {
      d += "<div>Guessed " + midpoint + " - Higher</div>";
      num1 = midpoint; 
    } else if (midpoint > guessNum)
    {
      d += "<div>Guessed " + midpoint + " - Lower</div>";
      num2 = midpoint; 
    } else if (midpoint == guessNum)
    {
      d += "<div>Guessed " + midpoint + " - Got it</div>";
    }
    } else if (guessNum > 500) 
    {
  
    if (midpoint < guessNum) {
      d += "<div>Guessed " + midpoint + " - Higher</div>";
      num2 = midpoint; 
     } else if (midpoint > guessNum)
     {
      d += "<div>Guessed " + midpoint + " - Lower</div>";
      num1 = midpoint;  
      } else if (midpoint == guessNum) 
      {
        d += "<div>Guessed " + midpoint + " - Got it</div>";
      }
    }
...