converting char array to string type

最新推荐文章于 2025-08-22 17:02:47 发布

转载最新推荐文章于 2025-08-22 17:02:47 发布 · 68 阅读

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原文链接：http://www.cnblogs.com/smartvessel/archive/2011/05/12/2044040.html

文章标签：

#c/c++

本文探讨了C++中处理含有嵌入空字符的C风格字符串到std::string的方法。通过逐字符复制和使用assign方法，避免了因遇到空字符而导致字符串截断的问题。

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std::string str;
char array[] = "Hello World";
for(int i = 0; array[i] != 0; i++)
str += array[i];
//-----------------------------------
std::string str;
char array[] = "Hello World";

str = array;

Use of NULL is discouraged in C++ because it can be redefined to be anything one wants -- c++ standards do not dictate what NULL should be.

The '\0' and 0 are one in the same thing. The compiler will translate '\0' to 0 during compilation.

All C-style strings are said to be NULL-terminated -- that definition is carry-over from C language. It really means that the end of the string is indicated by the byte which contains a 0.

you cannot assign C-strings that have enbedded 0s to std::string as I posted earlier. As you found out the assignment stops at the first 0. You could do it one character at a time, but then std::string is no longer an ascii string but a binary string, and most of the std::string methods cannot be used, again because of embedded 0s.

In this example, the output of the first cout is jest "Hello" because of the embedded 0.

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

int main()
{
    int i;
    char str[] = "Hello \0World";
    string s = str;
    cout << s << endl; << output = "Hello"
    int sz = sizeof(str);
    s = "";
    for(i = 0; i < sz; i++)
        s += str[i];

    cout << s << endl;
// now assign characters one at a time
    sz = s.length();
    for(i = 0; i < sz; i++)
        cout << s[i];
    cout << endl; output = "Hello World"
    return 0;

}

int main()
{
    int i;
    string s;
    char str[] = "Hello \0World";
    int sz = sizeof(str);
    s.assign(str,sz);
    sz = s.length();
    for(i = 0; i < sz; i++)
        cout << s[i];
    cout << endl;
    return 0;

}

转载于:https://www.cnblogs.com/smartvessel/archive/2011/05/12/2044040.html