Ubuntu g++；已安装，但当我尝试运行它时，我'；我听说它没有安装

我使用的是ubuntu 16.04，我已经安装了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.

~$ 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.

但是，当我尝试使用它进行编译时，或者如果我只是调用它，我会收到一条错误消息，说明没有安装g++

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

我已经尝试过

apt更新

和

apt升级

，但没有任何变化。还安装了Build essential软件包：

~$ 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.

~$ 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.

---

如何让g++工作？

安装有问题，或者后来被修改/损坏

重新安装它

sudo apt-get install --reinstall g++

---

尝试执行

gcc--version

是否尝试删除并重新安装它？@Bl4ckb0ne:gcc（Ubuntu 6.2.0-3ubuntu11~16.04）6.2.020160901@JohnZwinck很好，它只是起作用了。使用了

sudo apt get install--重新安装g++