Write a function named pop2 that takes an argument named list, which is the head cell of a linked list, and removes the first normal cell (not the head cell), and returns list (this is the difference from the last exercise). If there are no normal cells in the list (i.e. the list is empty), leave the list alone and return it. Code to construct an example linked list in the form used in the tests is given below.

var tail = { next: null };
var cell2 = { data: 12, next: tail };
var cell1 = { data: 45: next: cell2 };
var head = { next: cell1 };

javascript programming
exercise: functions 05

<html>
<script>

// ADD YOUR FUNCTION UNDER THIS LINE

var tailA = { next: null };
var cell2A = { data: 12, next: tailA };
var cell1A = { data: 45, next: cell2A };
var headA = { next: cell1A };
var cell0A = { data: 99, next: cell1A };
var headA2 = { next: cell0A };
var headB = { next: tailA };
  
var testAA = [
  [headA2,headA],
  [headB,headB]
];

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 = pop2;

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>list</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>