我有一个类，其方法应该返回一个字符串向量。 getCommVector方法必须将字符串数组的元素push_back为字符串向量，然后由该方法返回。当我尝试将字符串元素添加到字符串向量时，我得到：
libc++abi.dylib: terminate called throwing an exception
2Program ended with exit code: 0
我无法理解为什么我不能将push_back字符串传递给向量。有任何想法吗？ 提前谢谢！
感兴趣的代码段（建议后编辑）：
class Command {
public:
//Command (std::string, bool, bool);
void setOperators(std::string,bool, bool);
void analyseCommand();
Command();
std::vector<std::string> getCommVector ();
private:
int numOperators; //number of total commands
int opCount; //current command number
std::string input_string;
bool field_command, byte_command;
std::string commVector[3];
std::vector<std::string> finalCommVector;
void byte_analysis();
void field_analysis();
void decode_command();
void syntax_error();
void decode_error();
};
Command::Command() : numOperators(0), opCount(0), field_command(false),byte_command(false)
{
}
std::vector<std::string> Command::getCommVector ()
{
std::string s ="test";
finalCommVector.push_back("s");
return finalCommVector;
}
添加SSCE：
class Command {
public:
//Command (std::string, bool, bool);
void setOperators(std::string,bool, bool);
void analyseCommand();
Command();
std::vector<std::string> getCommVector ();
private:
int numOperators; //number of total commands
int opCount; //current command number
std::string input_string;
bool field_command, byte_command;
std::string commVector[3];
std::vector<std::string> finalCommVector;
void byte_analysis();
void field_analysis();
void decode_command();
void syntax_error();
void decode_error();
};
Command::Command() : numOperators(0), opCount(0), field_command(false),byte_command(false)
{
}
void Command::syntax_error()
{
std::cout<<"Incorrect Syntax Error: Usage: linuxcut -b num -f num \n";
exit(EXIT_FAILURE);
}
void Command::decode_error()
{
std::cout<<"Decode Error: Usage: linuxcut -b num -f num \n";
exit(EXIT_FAILURE);
}
void Command::analyseCommand()
{
if (byte_command) {
//start byte command analysys
byte_analysis();
}
else if (field_command)
{
//start field command analysys
field_analysis();
}
}
void Command::setOperators(std::string input_argument, bool is_field, bool is_byte)
{
input_string = input_argument;
field_command = is_field;
byte_command = is_byte;
}
std::vector<std::string> Command::getCommVector ()
{
std::string s = "ssd";
finalCommVector.push_back(s);
/*
for (int i = 0; i<sizeof(commVector); i++)
{
if (commVector[i] != "")
{
//debug
std::cout<<"asdas";
}
}
*/
return finalCommVector;
}
void Command::byte_analysis()
{
int next_state = 0;
int dashCount = 0;
int commVectIndex = 0;
//iterate through string and check if the argument is valid
for (int i= 0; i<input_string.length(); i++) {
switch (next_state) {
case 0: //start
//if character is a number:
if (isdigit(input_string.at(i)))
{
//first elemnt of command commVector is number
commVector[commVectIndex]+=input_string.at(i);
//DEBUG
std::cout<<commVector[commVectIndex];
next_state = 1;
}
//if character is a dash:
else if (input_string[i] == '-')
{
//increment dashCount
dashCount++;
//if next character in input_string is a number continue
if (isdigit(input_string[i+1])) {
commVector[commVectIndex]+=input_string.at(i);
commVectIndex++;
next_state = 1;
}
else //else error
{
syntax_error();
}
}
//if it's niether: error!
else
{
syntax_error();
}
break;
case 1:
//if next character is a number:
if (isdigit(input_string[i]))
{
commVector[commVectIndex]+=input_string.at(i);
next_state = 1;
}
//if next character is dash
else if (input_string[i] == '-'&& dashCount <= 3)
{
dashCount++;
//increment commandVectIndex
commVectIndex++;
next_state = 2;
commVector[commVectIndex]+=input_string.at(i);
//increment commandVectIndex to accomodate next operation
commVectIndex++;
}
//if it's niether: error!
else
{
syntax_error();
}
break;
case 2://previous character was dash
//if next character is number
if (isdigit(input_string[i]))
{
commVector[commVectIndex]+=input_string.at(i);
next_state = 1;
}
//if it's niether: error!
else
{
syntax_error();
}
break;
default:
syntax_error();
break;
}
}
}
void Command::field_analysis()
{
}
/*****************FUNCTIONS DEFINITIONS***************/
void print_usage() {
std::cout<<"Incorrect Syntax Error: Usage: linuxcut -b num -f num \n";
}
/*****************END OF FUNCTIONS DEFINITIONS***************/
/***************** MAIN ***************/
int main(int argc, char *argv[]) {
int opt= 0;
std::string byte = "-1-2,2",field = "";
std::string sub_arg_delimiter = ","; //delimiter for comma serparated arguments
static bool complement = false;
int diffOpt = 0; //stores the difference between optind and argc to read filenames in command
std::string fileName;
//Specifying the expected options
//The two options l and b expect numbers as argument
static struct option long_options[] = {
{"byte", required_argument, 0, 'b' },
{"field", required_argument, 0, 'f' },
{"complement", no_argument, 0, 0 },
{0, 0, 0, 0 }
};
Command testCommand;
testCommand.setOperators("-2-", false, true);
std::vector<std::string> trial = testCommand.getCommVector();
std::cout<<"filename:"<<fileName<<std::endl;
std::cout<<"Selected flags:\n"<< "b: "<< byte<<"\nf: "<<field<<"\ncomplement: "<<complement<<std::endl;
return 0;
}
答案 0 :(得分：5)
你正在迭代超出数组大小。 sizeof(commVector)以字节为单位返回数组的大小。
如果你有C ++ 11，你可以这样做：
for (const auto &s : commVector) {
if (s != "") {
// as before
}
}
或者至少这个（如果你只有部分C ++ 11支持）：
for (auto it = std::begin(commVector); it != std::end(commVector); ++it) {
std::string s = *it;
// the rest as before
}
没有C ++ 11，你至少可以这样做：
for (int i = 0; i < sizeof(commVector) / sizeof(commVector[0]); ++i) {
// the rest as before
}
或者提供自己的函数来获得正确的数组大小：
template <class T, size_t N>
size_t arraySize(const T (&)[N]) { return N; }
// Use:
for (size_t i = 0; i < arraySize(commVector); ++i) {
// the rest as before
}
答案 1 :(得分：2)
i<sizeof(commVector);
应该是
i<countof(commVector);
如果为编译器定义了countof / _countof。如果没有，您可以自己完成，通常定义为：
#define countof(a) (sizeof(a)/sizeof(a[0]))
我不会讨论在C ++中使用宏的问题：）
当然，你也可以使用常量，你的数组有固定数量的元素，但我想这只是一个例子。
sizeof返回对象的大小（在本例中为字符串数组）本身，而不是向量内的元素数。
因此，它等于数组元素的数量乘以单个字符串实例的大小，因此您尝试使用operator[]访问不存在的项目。
这也被打破了：
finalCommVector.push_back("s");
也许你的意思是：
finalCommVector.push_back(s);
答案 2 :(得分：0)
如果您需要的是std::string commVector作为std::vector<String>的数组，则可以使用std::vecor::assign：
finalCommVector.assign(commVector, commVector+3)
＆＃39; 3＆＃39;是数组的长度。