how to upgrade java 8 to 11 in ubuntu

1sudo apt install default-jdk
2

1sudo apt-get install openjdk-11-jdk
2
3$ sudo update-alternatives --config java
4There are 2 choices for the alternative java (providing /usr/bin/java).
5
6Selection    Path                                            Priority   Status
7
8* 0            /usr/lib/jvm/java-9-openjdk-amd64/bin/java       1500      auto mode
9  1            /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java   1500      manual mode
10  2            /usr/lib/jvm/java-9-openjdk-amd64/bin/java       1500      manual mode
11

1sudo apt-get update && sudo apt-get upgrade
2sudo apt-get install default-jdk