Relive thinking in Java

1. High precision

BigInteger, BigDecimal support for arbitrary-sized numbers can not be used operator operation speed relative to int, float slightly slower

2. Object Scope

{    new String ("AAA");}

Outside of this stack, the reference S has gone beyond its scope to exist, but the new String ("AAA") objects in this heap still exist in memory

At this point, Java garbage collection detects those unreferenced objects and then automatically frees the unused memory

3. Shift Operators

<< shift left Low 0

>> Right Move value is positive high 0 if negative high plug 1

>>> move right either positive or negative high plug 0

Note that negative numbers are complementary, for example 22:0001 0110

-22: First absolute value 0001 0110 anti-code 1110 1001 complement = anti-code +1 1110 1010

4.

Relive thinking in Java