GO Web Basics (001)

Learn from here

Https://golangcaff.com/docs/build-web-application-with-golang

25 keywords for 1.GO

Break default Func interface Selectcase

Defer go map struct chan else goto package

Switchconst Fallthrough If range typecontinue

For import return Var

Configuring the Environment

To define a variable rule:

Using the var keyword is the basic way to define variables for go, unlike the C language, where go puts the variable type behind the variable name:

Define a variable named "VariableName" with the type "types"

var variableName type

Define multiple variables

Defines three types that are "type" variables

var name1 name2 Name3 Type

Defining variables and initializing values

var name1 type = value

Simultaneous initialization of multiple variables

/*

Defines three types that are "type" variables and are initialized to the corresponding values respectively

Vname1 for V1,vname2 to V2,vname3 for v3

*/

var vname1,vname2 vname3 type = V1,v2,v3

/*

Define three variables that are initialized to their respective values

Vname1 for V1,vname2 to V2,vname3 for v3

Then go will help you initialize them based on the type of their corresponding values.

*/

Simple notation

var Vname1,vname2,vname3 = V1,v2,v3

Continue to simplify the wording

Vname1,vname2,vname3: = V1,v2,v3

Constants Define Const

BOOL defaults to False

Numeric type

String Go string is immutable

Iota Enum type

Go has a keyword iota, which is used when declaring an enum, and its default starting value is to add 1 to each additional line in 0,const.

const{

x = Iota//x = 0;

y = iota//y = 1;

z = Iota//z= 2;

When a w//constant declares an ellipsis, the default is the same literal as the previous value. Here implicitly says W = iota, so w = = 3. In fact, the above Y and Z can also not "= Iota"

}

Const V = iota//each time a const keyword is encountered, iota is reset, at which point v = = 0

Const (H, I, j = iota, iota, iota//h=0,i=0,j=0 Iota same row value)

Const (

A = iota//a=0

b = "B"

c = Iota//c=2

D, E, F = iota, iota, Iota//d=3,e=3,f=3

G = Iota//g = 4

)

Some rules of Go programming

The variable at the beginning of the capital letter is exportable, which is the public variable that the other package can read, and the lowercase letter begins with a non-exportable, private variable.

A function that starts with a capital letter is the same as a public function with a common keyword in class, and a private function that starts with a secret keyword.

Array expression arrays

var arr [N]type

in [N]type, n represents the length of the array, and type represents the types of the stored elements. Operations of an array are similar to other languages, and are read or assigned by []:

Slice dynamic Array

Slice has some simple operations

The default starting position for slice is 0,ar[:n] equivalent to ar[0:n]

The second sequence of slice is the length of the array by default, Ar[n:] equivalent to Ar[n:len (AR)]

If you get slice directly from an array, you can ar[:] because the default first sequence is 0, the second is the length of the array, which is equivalent to Ar[0:len (AR)]

Map

Make new operation

0 value