需要从字母数字字符串中的多个数字中查找特定数字

function findNumberInString(str, targetNumber) {
  let currentNumber = '';
  for (let i = 0; i < str.length; i++) {
    const char = str[i];
    if (!isNaN(char)) { // 判断字符是否为数字
      currentNumber += char;
    } else if (currentNumber !== '') { // 已经找到一个数字
      if (parseInt(currentNumber) === targetNumber) {
        return currentNumber;
      }
      currentNumber = ''; // 重置临时字符串
    }
  }
  return '未找到目标数字';
}

const inputString = 'a1b2c3d4e5';
const targetNumber = 3;
const result = findNumberInString(inputString, targetNumber);
console.log(result); // 输出：3