'data.value' is of type 'unknown'.
时间: 2024-01-24 21:01:44 浏览: 23
As an AI language model, I cannot tell you the exact meaning of this statement without context. However, in general, 'unknown' indicates that the type of data is not known or cannot be determined at compile time. This may happen when the type of data is determined dynamically or when the data is being parsed from an external source. In such cases, the programmer needs to use type assertions or type guards to ensure that the data is of the expected type before using it.
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https://github.com/leozhang1/QtInterpreter这个链接 Value.cpp代码 展示
以下是该链接中 Value.cpp 的代码:
```
#include "Value.h"
#include "Object.h"
#include <sstream>
Value::Value(int intValue)
: m_type(Int)
{
m_data.intValue = intValue;
}
Value::Value(double doubleValue)
: m_type(Double)
{
m_data.doubleValue = doubleValue;
}
Value::Value(bool boolValue)
: m_type(Bool)
{
m_data.boolValue = boolValue;
}
Value::Value(const std::string& stringValue)
: m_type(String)
{
m_data.stringValue = new std::string(stringValue);
}
Value::Value(Object* objectValue)
: m_type(ObjectPtr)
{
m_data.objectValue = objectValue;
}
Value::Value(const Value& other)
: m_type(other.m_type)
{
switch (m_type) {
case Int:
m_data.intValue = other.m_data.intValue;
break;
case Double:
m_data.doubleValue = other.m_data.doubleValue;
break;
case Bool:
m_data.boolValue = other.m_data.boolValue;
break;
case String:
m_data.stringValue = new std::string(*other.m_data.stringValue);
break;
case ObjectPtr:
m_data.objectValue = other.m_data.objectValue;
break;
}
}
Value::~Value()
{
if (m_type == String) {
delete m_data.stringValue;
}
}
Value::Type Value::type() const
{
return m_type;
}
int Value::asInt() const
{
if (m_type == Int) {
return m_data.intValue;
} else if (m_type == Double) {
return static_cast<int>(m_data.doubleValue);
} else if (m_type == Bool) {
return m_data.boolValue ? 1 : 0;
} else if (m_type == String) {
std::stringstream ss(*m_data.stringValue);
int i;
ss >> i;
return i;
} else if (m_type == ObjectPtr) {
throw std::runtime_error("Cannot convert object to int");
}
throw std::runtime_error("Unknown value type");
}
double Value::asDouble() const
{
if (m_type == Int) {
return static_cast<double>(m_data.intValue);
} else if (m_type == Double) {
return m_data.doubleValue;
} else if (m_type == Bool) {
return m_data.boolValue ? 1.0 : 0.0;
} else if (m_type == String) {
std::stringstream ss(*m_data.stringValue);
double d;
ss >> d;
return d;
} else if (m_type == ObjectPtr) {
throw std::runtime_error("Cannot convert object to double");
}
throw std::runtime_error("Unknown value type");
}
bool Value::asBool() const
{
if (m_type == Int) {
return m_data.intValue != 0;
} else if (m_type == Double) {
return m_data.doubleValue != 0.0;
} else if (m_type == Bool) {
return m_data.boolValue;
} else if (m_type == String) {
std::string stringValue = *m_data.stringValue;
return !stringValue.empty() && stringValue != "false" && stringValue != "0";
} else if (m_type == ObjectPtr) {
throw std::runtime_error("Cannot convert object to bool");
}
throw std::runtime_error("Unknown value type");
}
std::string Value::asString() const
{
if (m_type == Int) {
std::stringstream ss;
ss << m_data.intValue;
return ss.str();
} else if (m_type == Double) {
std::stringstream ss;
ss << m_data.doubleValue;
return ss.str();
} else if (m_type == Bool) {
return m_data.boolValue ? "true" : "false";
} else if (m_type == String) {
return *m_data.stringValue;
} else if (m_type == ObjectPtr) {
throw std::runtime_error("Cannot convert object to string");
}
throw std::runtime_error("Unknown value type");
}
Object* Value::asObject() const
{
if (m_type == ObjectPtr) {
return m_data.objectValue;
}
throw std::runtime_error("Value is not an object");
}
Value& Value::operator=(const Value& other)
{
if (this != &other) {
if (m_type == String) {
delete m_data.stringValue;
}
m_type = other.m_type;
switch (m_type) {
case Int:
m_data.intValue = other.m_data.intValue;
break;
case Double:
m_data.doubleValue = other.m_data.doubleValue;
break;
case Bool:
m_data.boolValue = other.m_data.boolValue;
break;
case String:
m_data.stringValue = new std::string(*other.m_data.stringValue);
break;
case ObjectPtr:
m_data.objectValue = other.m_data.objectValue;
break;
}
}
return *this;
}
```
这里是一个用于嵌入式解释器的 C++ 类库。Value 类是该库中的一个重要组成部分,它表示解释器中的值。包括整型、浮点型、布尔型、字符串和对象指针。Value 类提供了许多方法,用于获取 Value 对象的值,并且支持值之间的相互赋值。此外,Value 类还提供了析构函数,用于在对象生命周期结束时释放相应的资源。
解释:ValueError: Unknown format code '%' for object of type 'str'
Null is a term used in computing to represent the absence of a value or an empty value. In programming languages, null is often used to indicate the absence of an object, a variable, or a pointer. It is also used to indicate the end of a data stream, or the absence of a result or a response from a server. Null is different from zero or an empty string, as it represents the complete absence of a value.