Default conversion and forced conversion of data types in Java, java Data Type

Default conversion and forced conversion of data types in Java, java Data Type

Default conversion:

A: from low to high :(Byte short char)---Int---Long---Float---Double

B: Note:Byte short charThey do not convert each other. They are involved in the calculation and are first converted to the int type.

Forced type conversion:

Format: Target Data Type Variable = (target data type) (converted data)

Among them, string data is good for other data+The result is of the string type,+Here is the connector

Classic example:

1. JudgmentShort s1 = 1; s1 = s1 + 1; AndShort s1 = 1; s1 + = 1; Difference

Resolution:

　　Short s1 = 1; s1 = s1 + 1; Format Error

BecauseS1 + = 1The expression type is automatically upgraded during operation. The result isIntType, and then assignedShortType, the error of forced type conversion is reported.

　　Short s1 = 1; s1 + = 1; The format is correct.

BecauseS1 + = 1; Is the specified operator and the encoder performs special processing;

2,Float f= 3.4Correct?

Resolution:

Error

If the precision is not accurate, forced type conversion should be used, for example:Float f = (flat) 3.4OrFloat f = 3.4 f;

In Java, the default value without a decimal point isIntType. The default value with a decimal point isDoubleType

Both questions are Java interview questions, which are very basic and important.