Java Basic Learning Chapter 02 (data type conversion and fundamental questions)

1. Java Basic data type conversions

   Data types in Java, categorized as reference data types and basic data types. The basic data type is 8

   Integer: Byte 8-bit, short 16-bit, int 32-bit. Long 64 bits, (8 bits = 1 bytes)

   Float type: Float 32-bit, double64-bit

   Character type: Char

   Boolean Type: Boolean

Automatic type conversion

Conversion diagram

The positive direction is the auto-convert inverse direction cast (char--->double conversion and byte-to-double conversion)

Char-->int-->long-->float-->doubl

Byte-->shot-->int-->long-->float-->double

The interview questions are as follows

1. Will the following code compile pass?

public class test{public static void Main (string[] args) {byte a=1;    BYTE b=a+1; }} A: The type conversion error will be prompted when the a+1 operation is not automatically promoted to type int.

2. The following code compilation will pass, if compiled through, what output?

test{Main (string[] args) {a=;        B=++a; System:    println (+B);  }} A: Compiled through, because + + + + is the Java language specified by the operator, Java will be special processing. Output: b=2;

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Java Basic Learning Chapter 02 (data type conversion and fundamental questions)