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.
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:
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.
For example:
// Valid identifiers:
_geeks23
geeks
gek23sd
Geeks
geeKs
geeks_geeks
// Invalid identifiers:
212geeks
if
default
Note:
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
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!
What is a Constant or Const in Golang? Here's what you need to know about using constants in Go.
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.
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.
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 specify what type of data a valid Go variable can hold. In the Go language, types are divided into four categories as follows:
Go supports two main ways to pass arguments: Pass by Value and Pass by Reference. Go uses pass by value by default.
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.
Golang like most other programming languages has switch statement. Here is how to use switch statement 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 structs in Golang are temporary structures with no names used for one-time purposes, while anonymous fields allow embedding of unnamed fields.
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Operators allow us to perform different types of operations on operands. In Go language, operators can be classified based on their different functions.
_(underscore) in Golang is called Blank Identifier. Identifier is a user-defined name of program elements used for identification purposes.
Hello, World! is the first basic program in any programming language. You can write this first program in Golang by following the steps below.
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