# JavaScript Practice: Why does the variable len equal to -1?

Link to JavaScript Practice: Arrays, Loops, Objects, Iterators Question 2: https://www.codecademy.com/paths/full-stack-engineer-career-path/tracks/fscp-javascript-syntax-part-ii/modules/fecp-practice-javascript-syntax-arrays-loops-objects-iterators/articles/fecp-javascript-practice-arrays-loops-objects-iterators

``````  let charCount = 0;
let len = -1;

for (let i=0; i<str.length; i++) {
if (str[i] == char) {
charCount++;
if (charCount > 2) {
return 0;
}
if (len == -1) {
len = i;
} else {
len = i - len + 1
}
}
}
if (charCount < 2) {
return 0;
}

return len;
};

``````

Where do you get it that `len=-1`? Did you write this code, or is it the solution code?

Where do you get it that `len=-1` ?
Solution Code

I am wondering the same thing. The following block of code is hurting my brain:

I’m assuming that we’re still iterating through the string forwards, so as this happens, I’m also assuming that the value of len is getting updated. The formula of len = i - len + 1 in order to calculate and store the number of characters is really confusing to me. Any help with this?
Thanks!

• Ian