8. String to Integer.js

const myAtoi = (s) => {
    s = s.trim(); // remove leading/trailing spaces
  
    if (s.length === 0) return 0;
  
    let i = 0;
    let sign = 1;
    let result = 0;
  
    // handle optional sign
    if (s[i] === '+' || s[i] === '-') {
      if (s[i] === '-') sign = -1;
      i++;
    }
  
    // build the number from digits
    while (i < s.length && s[i] >= '0' && s[i] <= '9') {
      result = result * 10 + (s[i].charCodeAt(0) - '0'.charCodeAt(0));
      i++;
    }
  
    result *= sign;
  
    // clamp within 32-bit signed integer range
    const INT_MIN = -(2 ** 31);
    const INT_MAX = 2 ** 31 - 1;
  
    if (result < INT_MIN) return INT_MIN;
    if (result > INT_MAX) return INT_MAX;
  
    return result;
  };
  
  console.log(myAtoi("42")); // 42
  console.log(myAtoi(" -042")); // -42
  console.log(myAtoi("1337c0d3")); // 1337
  console.log(myAtoi("0-1")); // 0
  console.log(myAtoi("-91283472332")); // 0