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

Tony E
Tony E
5,802 Points
Posted by Tony E
Tony E
5,802 Points

Why does my code only work with document.write?

This is how I solved the problem, and although it's probably not great, it does seem to work. But if I use the 'getElementById' print function, only the last student entry appears. I was just wondering why one print method works but the other doesn't.

function print(message) {
 document.write(message);
}

for ( i = 0 ; i < students.length; i +=1 ) {
 var record = "<h2>Student name: " + students[i].name + '</h2>';
  record += '<p>' + 'Track: ' + students[i].track + '<br>'; 
  record += 'Achievements: ' + students[i].achievements + '<br>';
  record += 'Points: ' + students[i].points + '</p>';

  print(record);
}

2 Answers

jcorum
jcorum
71,830 Points

There are several issues here.

First, getElementById() isn't a print function. It's telling the print() function where to place the output on the page, viz., as the innerHTML of the element whose id is output. 

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

This function is called after the for loop, and passed a message created in the for loop:

for (var  i = 0; i < students.length; i += 1) {
    student = students[1];
    message += '<h2>Student: " + student.name + '</h2>';
    message += '<p>Track: " + student.track + '</p>';
    message += '<p>Points: " + student.points + '</p>';
    message += '<p>Achievements: " + student.achievements + '</p>';
}
print(message);

In your for loop you write over the record for the previous student with each new student, and call the print() function from within the loop. That could work, but each time you call the print() function you were writing to the same element's innerHTML. That's why you had to modify the print() function. But if you create the full message and then call the print() function outside the for loop, it will all come together.

Happy coding.

Tony E
Tony E
5,802 Points
Tony E
Tony E
5,802 Points

Thank you, sir.