Write a function named addXYObj that takes one argument named obj. If obj has both a property named x whose value is not undefined and one named y that is also defined, then add a new property named sum that is the sum of x and y. In either case, return obj.

javascript programming
exercise: functions 02

<html>
<script>

// ADD YOUR FUNCTION UNDER THIS LINE

var testAA = [
  [{x:1,y:2},{x:1,y:2,sum:3}],
  [{x:1,y:undefined},{x:1,y:undefined}],
  [{y:2},{y:2}],
  [{x:27,y:5},{x:27,y:5,sum:32}]
];

function cloneTree(obj) {
  if (obj === null)
    return null;
  if (typeof obj !== "object")
    return obj;
  var newobj = {};
  for (var prop in obj) {
    newobj[prop] = cloneTree(obj[prop]);
  }
  return newobj;
}

var argAAS = [];
for (var i=0;i<testAA.length;i++) {
  argAAS.push( [] );
  for (var j=0;j<testAA[i].length-1;j++) {
    argAAS[i].push( str(testAA[i][j]) );
  }
}

var testFunction = addXYObj;

function runTests(func,testAA) {
  var answerA = [];
  for (var i=0;i<testAA.length;++i)
    answerA.push( func.apply(null,testAA[i]) );
  return answerA;
}

function str(x) {
  return JSON.stringify(x);
}

function run() {
  var error = null;
  var answerA;
  try {
    answerA = runTests(testFunction, testAA);
  }
  catch (err) {
    error = err;
  }
  if (error!==null)
    document.write("<b>Runtime error!</b>  ("+error+")<br>");
  document.write("<table>");
  document.write("<tr>");
  document.write("<th>Result</th>");
  document.write("<th>Your Value</th>");
  document.write("<th>Correct Value</th>");
  document.write("<th>obj</th>");
  document.write("</tr>");
  var nArgs = testAA[0].length-1;
  for (var i=0;i<testAA.length;++i) {
    document.write("<tr>");
    if ( str(testAA[i][nArgs])==str(answerA[i]) )
      document.write("<td>pass</td>");
    else
      document.write("<td>FAIL</td>");
    document.write("<td><pre>"+str(answerA[i])+"</pre></td>");
    document.write("<td><pre>"+str(testAA[i][nArgs])+"</pre></td>");
    for (var j=0;j<nArgs;j++)
      document.write("<td>"+argAAS[i][j]+"</td>");
    document.write("</tr>");
  }
  document.write("</table>");
}

run();
</script>

<style>
table { border-spacing: 15px 5px; }
th { text-align:center; }
td { text-align:center; }
</style>
</html>