The difference between equals and = = in Java

In the project, find trial = = To compare two uuid, always false, change to. Equals, returns True.

The original = = comparison is memory address, more for the comparison of value types

Information about the type of value attached

Four categories: 1, Integer 2, float type 3, character 4, logic type

Eight kinds:
1, integral type 3 kinds of Byte,short,int,long

2, Float type 2 kinds of float,double

3, character type 1 char

4, Logic type 1 Boolean

And the UUID is not a value type, we take = = to compare the address, of course always return false.

At this point, try. Equals to compare the data pointed to by the memory and return the correct comparison results.

conclusion, if it is a value type, use = =, if it is not a value type, it is used. equals

The difference between equals and = = in Java