菜鸟求教:为什么会出现变量重定义呢
#include <iostream>
#include <string>
using std::cout;
using std::cin;
using std::endl;
using std::string;
int main() {
string text; // The string to be sorted
const string separators = " ,.!:;\ "\?\n\t "; // Word delimiters
// Read the string to be searched from the keyboard
cout < < endl < < "Enter a string terminated by #: " < < endl;
std::getline(cin, text, '# ');
// Count the words in the text
size_t start = text.find_first_not_of(separators); // Word start index
size_t end = 0; // End delimiter index
int word_count = 0; // Count of words stored
while(start != string::npos) {
end = text.find_first_of(separators, start + 1);
if(end == string::npos) // Found a separator?
end = text.length(); // No, so set to last + 1
word_count++; // Increment count
// Find the first character of the next word
start = text.find_first_not_of(separators, end + 1);
}
// Allocate an array of pointers to strings in the free store
string** pwords = new string*[word_count];
start = text.find_first_not_of(separators); // Word start index
end = 0; // End delimiter index
int index = 0; // Current array index
while(start != string::npos) {
end = text.find_first_of(separators, start + 1);
if(end == string::npos) // Found a separator?
end = text.length(); // No, so set to last + 1
pwords[index++] = new string(text.substr(start, end - start)); // Store the word
// Find the first character of the next word
start = text.find_first_not_of(separators, end + 1);
}
// Sort the words in ascending sequence using the array of pointers
int lowest = 0; // Index of lowest word
for(int j = 0; j < word_count - 1 ; j++) {
lowest = j; // Set lowest
// Check current against all the following words
for(int i = j + 1 ; i < word_count ; i++)
if(*pwords[i] < *pwords[lowest]) // Current is lower?
lowest = i;
if(lowest != j) { // Then swap pointers
string* ptemp = pwords[j]; // Save current
pwords[j] = pwords[lowest]; // Store lower in current
pwords[lowest] = ptemp; // Restore current
}
}
// Output up to six words to a line in groups starting with the same letter
char ch = (*pwords[0])[0]; // First letter of first word
int words_in_line = 0; // Words in a line count
for(int i = 0; i < word_count ; i++) {
if(ch != (*pwords[i])[0]) { // New first letter?
cout < < endl; // Start a new line
ch = (*pwords[i])[0]; // Save the new first letter
words_in_line = 0; // Reset words in line count
}
cout < < *pwords[i] < < " ";
if(++words_in_line == 6) { // Every sixth word
cout < < endl; // Start a new line
words_in_line = 0;
}
}
// Delete words from free store
for(int i = 0 ; i < word_count ; i++)
delete pwords[i];
// Now delete the array of pointers
delete [] pwords;
cout < < endl;
return 0;
}
我编译这段代码会出现for语句里的i变量重复定义的错误--- 'i ' : redefinition; multiple initialization
这是怎么回事啊大哥大姐们？
[解决办法]
编译器不支持新C＋＋标准
在别的循环中不用i就是的，改成k,l,m,n...随你
[解决办法]
把int i 提取出来定义就可以了
[解决办法]
你把变量声明定义移到for循环外面
[解决办法]
例：
for(int i=0;i<10;i++)
{
for(int i=0;i<10;i++)
{
cout<<"*";
}
cout<<endl;
}
用VC6编译不通过，但VC2005就可以通过，C++标准是允许这样的代码的。
