function getBaseFileName(fullPath) {
    return fullPath.replace(/.*[\/\\]/, '');
}

// 测试
const filePath = 'C:\\Users\\username\\Documents\\example.txt';
console.log(getBaseFileName(filePath));  // 输出: example.txt

const filePath2 = '/home/user/documents/example.txt';
console.log(getBaseFileName(filePath2));  // 输出: example.txt