How to use constants in Golang
What is a Constant or Const in Golang? Here's what you need to know about using constants in Go.
How to use variables in Golang
In programming languages, identifiers are used for exactly what their name suggests. In other words, identifiers are user-defined names for program elements. In Go, identifiers can be variable names, function names, constants, statement labels, package names, or types. Here's what you need to know about using identifiers in Golang.
For example:
package main
import "fmt"
func main() {
var name = "Quantrimang.com"
}There are a total of three identifiers available in the above example:
- main : Package name
- main : Name of the function
- name : Name of the variable
Variable Definition Rules: There are some valid rules for defining valid Go variables. These rules need to be followed, otherwise we will get compilation errors.
- An identifier name must begin with a letter or an underscore(_). And it can contain the letters 'a-z' or 'A-Z' or the numbers 0-9 as well as the character '_'.
- The identifier name cannot begin with a digit.
- Identifier names are case sensitive.
- Keywords are not allowed as identifiers.
- There is no limit on the length of an identifier name, but an optimal length of 4 – 15 letters is recommended.
For example:
// Valid identifiers:
_geeks23
geeks
gek23sd
Geeks
geeKs
geeks_geeks
// Invalid identifiers:
212geeks
if
defaultNote:
In Go, there are a number of pre-declared identifiers available for constants, types, and functions. These names are not reserved, you are allowed to use them in declarations. Here is a list of pre-declared identifiers:
Cho hằng số:
true, false, iota, nil
Cho các kiểu:
int, int8, int16, int32, int64, uint,
uint8, uint16, uint32, uint64, uintptr,
float32, float64, complex128, complex64,
bool, byte, rune, string, error
Cho các hàm:
make, len, cap, new, append, copy, close,
delete, complex, real, imag, panic, recover- A variable represented by an underscore character (_) is called an empty identifier. It is used as an anonymous placeholder instead of a regular identifier and has special meaning in declarations, as an operand, and in assignments.
- A variable that is accessible from another package is called an exported identifier. Exported identifiers are those identifiers that satisfy the following conditions:
- The first character of the exported identifier name must be an uppercase Unicode letter.
- The identifier must be declared within a package block or as the name of a variable, function, type, or method within that package.
In the example below, file1.go contains an exported variable named ExportedVariable , which is accessible within the same file. It also imports the file2 package and accesses the exported variable AnotherExportedVariable from file2.go . By running go run file1.go , it will print the value of ExportedVariable (“Hello, World!”) from file1.go and the value of AnotherExportedVariable (“Greetings from file2!”) from file2.go . This demonstrates the concept of exported variables being accessible from another package in Go.
Example of file2:
//file2.go
package file2
// Exported variable
var AnotherExportedVariable = "Greetings from file2!"
Example of file1:
// file1.go
package main
import (
"fmt"
"github.com/yourusername/project/file2"
)
// Biến được xuất
var ExportedVariable = "Hello, World!"
func main() {
// Truy cập biến đã xuất trong cùng file
fmt.Println(ExportedVariable)
// Truy cập biến đã xuất từ gói khác
fmt.Println(file2.AnotherExportedVariable)
}
Result:
Hello, World!
Greetings from file2!Volatile functions in Golang
Variadic functions in Go allow you to pass a variable number of arguments to a function. Here's everything you need to know about variadic functions in Golang.
Named return parameters in Golang
In Golang, named return parameters are often referred to as named parameters. Golang allows naming the return parameters or results of functions in the function signature or definition.
Keywords in Go
Keyword - Keywords are words in a language that are used for some internal processes or represent some predefined actions. Here is what you need to know about keywords in Golang.
Data types in Golang
Data types specify what type of data a valid Go variable can hold. In the Go language, types are divided into four categories as follows:
Function arguments in Golang
Go supports two main ways to pass arguments: Pass by Value and Pass by Reference. Go uses pass by value by default.
Function returning multiple values in Golang
In Go language, you are allowed to return multiple values from a function, using the return statement. In other words, in a function, a return statement can return multiple values.
Switch Statement in Go
Golang like most other programming languages has switch statement. Here is how to use switch statement in Golang.
Cases to know when using selection statements in Golang
In this article, we will learn how to use default case to avoid deadlock. But first, we will learn what is deadlock case when using select command in Golang?
Anonymous structures and fields in Golang
Anonymous structs in Golang are temporary structures with no names used for one-time purposes, while anonymous fields allow embedding of unnamed fields.
How to use Rune in Golang
What is Rune in Golang? How to use Rune in Golang? This article will give you the answer.
How to use operators in Golang
Operators allow us to perform different types of operations on operands. In Go language, operators can be classified based on their different functions.
Void identifier in Golang
_(underscore) in Golang is called Blank Identifier. Identifier is a user-defined name of program elements used for identification purposes.
How to create basic program in Golang
Hello, World! is the first basic program in any programming language. You can write this first program in Golang by following the steps below.
How to Install Go on Windows
Golang can be easily installed on Windows. Here is a step-by-step guide to install Golang on Windows.
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