检查字符串中的字符是否为空格不起作用

Question

我需要在字符串中每个包含 6 个数字的部分之前添加两个零，而不删除这些部分之间的空格。这是代码：

#include <iostream>
#include <string>
using namespace std;

int main()
{
    string EightByte_BinaryBuffer = "010000 010100 001001 000011"; //can provide full code with reading input from user if needed

    for (int i = 0; i < EightByte_BinaryBuffer.length(); i++)
    {
        if (i == 0)
        {
            EightByte_BinaryBuffer.insert(i, "00");
        }
        else if (isspace(EightByte_BinaryBuffer.at(i)) == true) //output console just stays black for minute without any changes
        {
            EightByte_BinaryBuffer.insert(i, "00");
        }
    }
    cout << EightByte_BinaryBuffer << endl;
}

我也尝试过这个替代方案，但它也不起作用：

#include <iostream>
#include <string>
using namespace std;

int main()
{
    string EightByte_BinaryBuffer = "010000 010100 001001 000011"; //can provide full code with reading input from user if needed

    for (int i = 0; i < EightByte_BinaryBuffer.length(); i++)
    {
        if (i == 0)
        {
            EightByte_BinaryBuffer.insert(i, "00");
        }
        else if (EightByte_BinaryBuffer[i] == ' ')
        {
            EightByte_BinaryBuffer.insert(i, "00");
        }
    }
    cout << EightByte_BinaryBuffer << endl;
}

对于上下文，我正在尝试复制一个 Base64 转换器，但停留在步骤 5（将六位字节转换为八位字节）。这是完整的算法：https://base64.guru/learn/base64-algorithm/encode

Answer 1

感谢@brian61354270 指出我在“i”计数器上的错误，我能够修复它：

#include <iostream>
#include <string>
using namespace std;

int main()
{
        for (int i = 0; i < EightByte_BinaryBuffer.length(); i++)
        {
            if (i == 0)
            {
                EightByte_BinaryBuffer.insert(i, "00");
                i += 2;
            }
            else if (EightByte_BinaryBuffer[i + 1] == ' ')
            {
                EightByte_BinaryBuffer.insert(i + 2, "00");
                i += 2;
            }
        }       
}

@paulmckenzie 还建议使用输入流的替代方案：

//explanation of how this code works can be found in comments under the question

#include <iostream>
#include <string>
#include <sstream>

int main()
{
    std::string EightByte_BinaryBuffer = "010000 010100 001001 000011"; 
    std::istringstream strm(EightByte_BinaryBuffer);
    std::string small_buf;
    std::string new_buf;
    while (strm >> small_buf)
        new_buf.append("00" + small_buf + " ");
    new_buf.pop_back();        
    std::cout << new_buf;
}

谢谢大家的帮助。