QVector & ltdouble & gt？ vec
vec . append( 1. 1)；
vec . append(2.2)；
vec . append(3.3)；
vec . append(4.4)； Please find other reasons or set breakpoints on
QVector & ltdouble & gt？ vec
vec . append( 1. 1)；
vec . append(2.2)；
vec . append(3.3)；
vec . append(4.4)； Please find other reasons or set breakpoints on the above four append statements to see how the contents of the vec container change when each statement is executed. It may be rewritten after the task is assigned.
Besides, could it be that you redefined the double type? Try qvector
QVector & ltqreal & gt？ vec
vec . append( 1. 1)；
vec . append(2.2)；
vec . append(3.3)；
vec . append(4.4)；