Qt对象实例化查询

Question

QObject *obj;
...
if ( /* obj is already instantiated */ ) {
    ;
} else {
    obj = new QObject();
}

我的查询是if的条件

Answer 1

1)将对象指针初始化为NULL

2)在if语句中检查NULL

QObject *obj = NULL;
...
if ( obj != NULL ) {
    ;
} else {
    obj = new QObject();
}