QJSValueIterator 类

QJSValueIterator 类提供 Java 样式迭代器为 QJSValue . 更多...

头: #include <QJSValueIterator>
CMake: find_package(Qt6 REQUIRED COMPONENTS Qml)
target_link_libraries(mytarget PRIVATE Qt6::Qml)
qmake: QT += qml

公共函数

QJSValueIterator (const QJSValue & object )
~QJSValueIterator ()
bool hasNext () const
QString name () const
bool next ()
QJSValue value () const
QJSValueIterator & operator= (QJSValue & object )

详细描述

The QJSValueIterator constructor takes a QJSValue as argument. After construction, the iterator is located at the very beginning of the sequence of properties. Here's how to iterate over all the properties of a QJSValue :

QJSValue object;
...
QJSValueIterator it(object);
while (it.hasNext()) {
    it.next();
    qDebug() << it.name() << ": " << it.value().toString();
}
					

The next () advances the iterator. The name () 和 value () functions return the name and value of the last item that was jumped over.

Note that QJSValueIterator only iterates over the QJSValue 's own properties; i.e. it does not follow the prototype chain. You can use a loop like this to follow the prototype chain:

QJSValue obj = ...; // the object to iterate over
while (obj.isObject()) {
    QJSValueIterator it(obj);
    while (it.hasNext()) {
        it.next();
        qDebug() << it.name();
    }
    obj = obj.prototype();
}
					

另请参阅 QJSValue::property ().

成员函数文档编制

QJSValueIterator:: QJSValueIterator (const QJSValue & object )

构造迭代器为遍历 object . The iterator is set to be at the front of the sequence of properties (before the first property).

[noexcept] QJSValueIterator:: ~QJSValueIterator ()

销毁迭代器。

bool QJSValueIterator:: hasNext () const

Returns true if there is at least one item ahead of the iterator (i.e. the iterator is not at the back of the property sequence); otherwise returns false.

另请参阅 next ().

QString QJSValueIterator:: name () const

Returns the name of the last property that was jumped over using next ().

另请参阅 value ().

bool QJSValueIterator:: next ()

Advances the iterator by one position. Returns true if there was at least one item ahead of the iterator (i.e. the iterator was not already at the back of the property sequence); otherwise returns false.

另请参阅 hasNext () 和 name ().

QJSValue QJSValueIterator:: value () const

Returns the value of the last property that was jumped over using next ().

另请参阅 name ().

QJSValueIterator &QJSValueIterator:: operator= ( QJSValue & object )

Makes the iterator operate on object . The iterator is set to be at the front of the sequence of properties (before the first property).