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JavaScript JavaScript Loops, Arrays and Objects Tracking Data Using Objects The Build an Object Challenge, Part 2

Matthew Goldwater
Matthew Goldwater
3,859 Points
Posted by Matthew Goldwater
Matthew Goldwater
3,859 Points

Why does my output start with undefined?

Everything else in my code works well. I just can't figure out why it says undefined at the top of my page when I preview it. I'd appreciate any help.

Here's my code: 

var students = [
  {name: 'Tom', track: 'ios' , achievements: 4, points: 23},
  {name: 'Bob', track: 'ux', achievements: 5, points: 34},
  {name: 'Zoe', track: 'ui', achievements: 2, points: 76},
  {name: 'So',  track: 'web', achievements: 1, points: 52},
  {name: 'Hal', track: 'osx', achievements: 9, points: 98}
];

var html;

function print(message) {
  var outputDiv = document.getElementById('output');
  outputDiv.innerHTML = message;
}

function buildContent(arr) {
  for (key in students) {
    html += '<p>' + '<strong>' + 'Student: ' +  
students[key].name + '</strong>' 
+ '<br><br>' + ' Track: ' 
+ students[key].track + '<br><br>' 
+ ' Points: ' + students[key].points 
+ '<br><br>' +  ' Achievements: ' 
+ students[key].achievements 
+ '<br><br>' + '</p>'
  }
  return html;
}
print(buildContent(students));

1 Answer

Michal Jankowski
Michal Jankowski
4,051 Points

You should declare 'var html' as an empty string: var html = ' '.

I am not sure why is that, but had the same problem yestarday ;)