Golang Notes--data types

This is a creation in Article, where the information may have evolved or changed.

1, 25 keywords

Program declaration: Import, Package

Program entity declaration and definition: Chan, const, Func, interface, map, struct, type, var

Program Flow control: Go, select, break, case, continue, default, defer, else, Fallthrough, for, Goto, if, range, return

2. Type

18 Basic types: bool, String, Rune, byte, int, uint, int8, uint8, Int16, UInt16, Int32, UInt32, Int64, UInt64, float32, float64, C Omplex64, complex128

7 Composite types: Array, struct, function, interface, slice, map, channel

The declaration of a type begins with the type keyword, then a custom identifier name, followed by the name of the base type or the definition of a composite type.

3. Operator

List some special operators, such as <<, >>, &, &^,!, <-, etc.

4. Special NULL Identifier: _

5. Expression

A special expression has a type assertion, and if you determine the type of an expression X is T, the expression is X. (t), meaning that x is not nil and the value stored in it is type T. There are two cases where x is a value of an interface type, such as interface{} (100) if it is determined that 100 is of type int. (int); If x is not the value of the one-year interface type, then T is required to be an interface type, which means that assertion X implements the interface of T.