int

int8

int16

int32

int64

uint

uint8

uint16

uint32

uint64

float32

float64

For splicing

Auxiliary usage using strings package

The double quotes "" inside Println() need to be escaped, otherwise it will cause output errors. When escaping, you can write the content to be output and then copy it into the double quotes, so that the compiler can automatically escape

Println() can also use backticks ` `, and newlines can be added inside the backticks.

When splicing strings, you cannot connect numbers. You need to convert the numbers into strings first and then splice them. Use strconv.Itoa(123) to convert 123 into a string.

What you get using the function len() is the byte length of the string, not the number of characters. Use utf8.RuneCountInString() to get the number of characters

It is bytes, essentially uint8, which is also used to represent ASCII codes. The corresponding operations are in the bytes package.

[ ]byte slices can be converted to and from strings.

var a [ ]byte = 'a' When assigning a value using single quotes, you can only use a single character. At this time, the ASCII code value of a is 97.

var a [ ]byte = "hello" can be assigned to a string when using double quotes

And: (a && b)

OrOr: ( a || b)

Negation: (!a)

Hold down the command and click on the package function to jump into the package to see the relevant explanations.

declare and assign

GO type inference

Can only be used for local variables

You can infer it yourself without the type.

Control constant initialization

However, using iota’s mathematical operations, including displacement operations

keyword func

Function name

parameter list

return value

A function calls itself internally

If the recursion is nested too deeply, stack overflow may occur.

function as variable

local function

function as return value

anonymous function

Closure

functions as types

last parameter

Equivalent to using slices

First in, last out

Principles for determining values

Modify return value

Implementation principle

Executed just before the function returns, called: delayed call

if

if else

if else if

for range loop

for i loop

for condition loop

There can be a default branch

No need to break

Compilation can be switched through instructions

direct initialization

make initialization

arr[start:end]

arr[start:]

arr[:end]

Does it contain data?

Taking expansion as the criterion

direct initialization

make initialization

val,ok = m[key]

val = m[key]

The traversal results are different. k and v are in one-to-one correspondence, but the order is not certain.

Struct{}

&Struct{}

new(Struct)

Assign values ​​in order

Assign value by name

Only pointers can be used

Use pointers when in doubt