Understanding Uninitialized Variables will not "test"

Tell us what’s happening:
Nothing happens when I press the button “Run the Tests”. Is this normal? Am I doing something wrong or is there a bug?

Your code so far

// Initialize these three variables
var a = 5;
var b = 10;
var c = I am a;

// Do not change code below this line

a = a + 1;
b = b + 5;
c = c + " String!";

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:61.0) Gecko/20100101 Firefox/61.0.

Link to the challenge:

c is supposed to be string, at the minute in your code it is not.

Thanks Dan. I still don’t understand why the Test would not run but it works once I corrected the string.

Basically it will be trying to look up I (and would try to look up am and a if it hadn’t already errored) as if it was a variable, so things will sometimes break in strange ways