We all know that polymorphisms in CPP depend on virtual tables and virtual pointers, so when are virtual tables generated? Is it before or after the constructor is executed? And where are the virtual watches stored? ...
Why do I get an error when I use var outside? You won t make a mistake in it? function fn(x=8){ var x = 89; console.log(x); } fn(); let y = 7; var y = 8; ...
how to make the app boot page adapt to different resolutions of Android phones without losing important information such as text ...
after MySQL looks up data, for example, the following data is returned after executing a lookup statement: RowDataPacket { ID: 1, issue: 704929 , userName: , group: , oper: , num: 6 , score: 50 , time: 2018-09-20T09:56:39.000Z, bon...
see this piece of code, as follows: function foo() { console.log( this.a ); } var obj2 = { a: 42, foo: foo }; var obj1 = { a: 2, obj2: obj2 }; obj1.obj2.foo(); 42 how should I understand...
there is a database for storing user behavior data, which has been divided into more than 1450 tables, and the amount of data in it is so large that the command line use database cannot be accessed for a long time. However, it is very fast to configure ...