& amp：

& operator, used to force a string connection between two expressions.

& identifier, the type declaration character of Long is ampersand; )。 & amph and & ampo as prefixes stand for 16 hexadecimal number and octal number respectively.

Numbers in the appropriate range, prefixed with &; H, which can directly represent hexadecimal digits. For example, the hexadecimal notation & H 10 stands for decimal 16.

Add & before the appropriate numerical range; O to directly represent octal numbers. For example, octal notation and O 10.

Represents decimal 8.

+ :

Arithmetic operator+operator, used to calculate the sum of two numbers.

Concatenation operator,+operator is used to splice strings.

The+operator may not be sure whether to do addition or string concatenation. To avoid confusion, please use&; ?

Operator and improve the readability of program code.