converting char array to string type

std::stringstr;

chararray[]="Hello World";

for(inti=0; array[i]!=0; i++)

str+=array[i];

//-----------------------------------

std::stringstr;

chararray[]="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>

usingnamespacestd;



intmain()

{

inti;

charstr[]="Hello \0World";

strings=str;

cout<<s<<endl;<<output="Hello"

intsz=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"

return0;


}
intmain()

{

inti;

strings;

charstr[]="Hello \0World";

intsz=sizeof(str);

s.assign(str,sz);

sz=s.length();

for(i=0; i<sz; i++)

cout<<s[i];

cout<<endl;

return0;


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

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