Question

I have this code

if(!(lotNo.charAt(0) >= "0" && (lotNo.charAt(0) <= "7"))) {
    // if the first character is not within these boundaries
    return false;
}
return true;

This method leaves me with an error saying bad operator type? Although it was supposed to check whether the first character in a String was between 0 and 7. Am I on the right lines?

Answer 1

You are comparing to strings instead of chars. Try:

if (!(lotNo.charAt(0) >= '0' && (lotNo.charAt(0) <= '7'))) { // if the first character is not within these boundaries
    return false;
}
return true;

"0" <– String with one char, '0'
'0' <– char, the character '0'