从字符串中提取整数-包括负整数

function extractIntegerFromString(str) {
  let result = 0;
  let isNegative = false;
  let foundNumber = false;

  for (let i = 0; i < str.length; i++) {
    const char = str[i];

    if (char === '-') {
      if (foundNumber) {
        break;
      }
      isNegative = true;
    } else if (char >= '0' && char <= '9') {
      result = result * 10 + parseInt(char);
      foundNumber = true;
    } else if (foundNumber) {
      break;
    }
  }

  return isNegative ? -result : result;
}

const str = "abc-123def456";
const extractedInteger = extractIntegerFromString(str);
console.log(extractedInteger); // 输出: -123