Question

I need a method helping me, to reach variables named like ‘comboBox1’, ‘comboBox2’ etc each by each in a loop. I’d like to change code like:

//proceed comboBox1 //proceed comboBox2 //proceed comboBox3 //proceed comboBox4 //proceed comboBox5 //proceed comboBox6 

Into:

for (int i = 1; i < numberOfBoxes; i++) {     //proceed comboBox(i) } 

I tried to find somthing like ‘eval’, but google didn’t give anything matching. I also tried preprocessing the name with operator ## but it seems there’s no way to put current integer value to the macro.

Answer 1

The simplest solution is to put them all in an array and iterator over that:

// I've made up a type, but you get the idea. std::vector<ComboBox *> combos; combos.insert(comboBox1); combos.insert(comboBox2); combos.insert(comboBox3); combos.insert(comboBox4); combos.insert(comboBox5); combos.insert(comboBox6); 

Now you can iterate over combos. The main problem is that c++ doesn’t have reflection. So you can’t generated a string at runtime and get the address of an object or function like you can in some other languages.

EDIT: I just saw that you are using Qt. In that case, you should use:

QList<T> qFindChildren ( const QObject * obj, const QString & name ); 

or

QList<T> qFindChildren ( const QObject * obj, const QRegExp & regExp); 

This lets you get a list based on runtime generated names. For example:

QList<QComboBox *> combos = qFindChildren(ui, QRegExp('combo[0-9]+')); 

then you can just iterate over that!