8 pictures Understand Java, 8 pictures Understand java

8 pictures Understand Java, 8 pictures Understand java

A picture is better than a thousand words. The illustration below is from the Java tutorial on the Program Creek website. Currently, they have the most votes.

1. character string immutability

The following figure shows what the code has done.

String s = "abcd"; s = s. concat ("ef ");

2. Differences between equals () and hashCode () Methods

HashCode is designed to improve performance. The difference between the equals () method and the hashCode () method is:

3. Java exception class hierarchy

The red part in the figure shows an exception. They must be captured or declared as throwing this exception in the function.

4. Hierarchy of collection classes

Note the differences between Collections and Collections. (Collections contains various static polymorphism methods related to Set Operations)

5. Java synchronization

The Java synchronization mechanism can be illustrated by analogy between buildings.

6. Alias

Aliases mean that multiple variables point to the same updatable memory block. These aliases are different object types.

7. Heap and stack

The diagram shows the location of the method and object in the runtime memory.

8. Data Area During Java VM running hours

The graphic shows the data area of the entire VM runtime.

I have a public account, and I often share some Java-related dry goods. If you like my share, you can search for "Java head" or "javatuanzhang" to follow up.