I need explanation

Question

Hi! I wrote such an answer for the test:

function main() {
var totalPrice = parseInt(readLine(), 10)

if (totalPrice <= 999){

console.log("0%")
}
else if (totalPrice <= 2999) {
console.log("10%")
}

else if (totalPrice <= 4999) {
console.log("30%")

}
else
{
console.log("50%")
}
}

I passed the test, but I have a question. If i write 800 - it is smaller, than 999, but it is also smaller, than 2999 and 4900. Why my solution is right?

Answer 1

Is it possible to make such strings as 5<a>2 in js?

Answer 2

And when i write 800 it is true for every string. I know, that my answer is right, but i see no logic. Why it returns true for correct segment, while the number is correct for every one of them?