#includeint main() { QSizeF size(10.5, -5.0); if (size.isValid()) { // Do something } else { // Handle invalid size } return 0; }
#includeIn this example, a QSizeF object called "size" is created with the values (2.5, 8.0). The method "isValid" is called on the object, which returns true since both size values are positive. This example then calculates the area of the object and stores it in a variable called "area". The Qt library is the package library used for QSizeF isValid.int main() { QSizeF size(2.5, 8.0); if (size.isValid()) { // Calculate area float area = size.width() * size.height(); } else { // Handle invalid size } return 0; }