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

Why do you need to assign an empty string to the message variable to work?

It doesn't make sense on why you need to assign the 'message' variable an empty string before adding anything to it.

var message = '';

for (var i = 0; i < students.length; i += 1) {
  studentName = students[i];
  message += '<h2>Student: ' + + '</h2>';

1 Answer

Robert Stefanic
Robert Stefanic
35,060 Points

Because if you do not, then the value of message will be undefined, and JavaScript doesn't know how to add undefined and a string.

This is why you have to initialize the variable to a string, because JavaScript does know how to concatenate two strings.