安装了g ++，但是当我尝试运行它时，我告诉它没有安装

Question

我使用的是ubuntu 16.04并安装了g ++：

~$ sudo apt install g++
Reading package lists... Done
Building dependency tree       
Reading state information... Done
g++ is already the newest version (4:5.3.1-1ubuntu1).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

但是，当我尝试使用它进行编译时，或者如果我只是调用它时，我收到一条错误消息，指出未安装g ++。

~$ g++
The program 'g++' is currently not installed. You can install it by typing:
sudo apt install g++

我已经尝试了apt update和apt upgrade，但没有任何变化。还安装了构建基本包：

~$ sudo apt-get install build-essential
Reading package lists... Done
Building dependency tree       
Reading state information... Done
build-essential is already the newest version (12.1ubuntu2).
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

我怎样才能使用g ++？

Answer 1

安装有问题，或者已经修改/损坏。

重新安装。

sudo apt-get install --reinstall g++