The difference between equals () and "= =" in Java

1. For the underlying data type, use "= =" to compare the values for equality;

2. For composite data types (classes), the Equals () and "= =" effects are the same, both of which are compared to the storage address of the object in memory (specifically, the heap memory address).

3. For a type that overrides the Equals () method for string, Integer, date, and so on, "= =" compares the stored memory address. The result of equals () is determined by the overwritten code.

In the 4.string type, equals () compares two strings for the same content. Such as:

String S1 = "Hello"; String s2 = "Hello"; s1.equals (s2) returns TRUE;S1==S2 returns true;string S1 = "Hello"; String s2 = new String ("Hello"), s1.equals (S2) returns true, but S1==s2 returns false;

　　

The difference between equals () and "= =" in Java