Java Learning Notes

1. Case sensitivity

2. Naming specification

3. Key words

4. Data type

Floating-point type in the decimal value is not accurate, can only be very similar to the number and approximate value

The difference between a float and a double

Double the valid bit is 15-16 bits, if this range is exceeded, the last one is given randomly.

Double e=123.45678900000006//This is 17 bit, but the result thought it might be 123.4567890000001, 123.4567890000009, 123.456789

Boolean type

Character type

Data type conversion-default conversion (large to small)

Data type conversions-casts (small to large)

Data type conversion-size capacity data blending operations

Shaping and shaping operations, the result is plastic, without strong transfer such as:

Java Learning Notes