Variables In Golang
- Variable in Golang or any other programming language is used to hold the data value. It could hold the value of type int, float, string, boolean, etc.
- Variables in Golang are defined using the keyword var.
- A variable can be defined either inside a main() function or outside a main() function in the same way.
- You can define a list of variables in a single line by just writing the var keyword and then comma separating each variable name.
Example to Define A Variable
package main
import "fmt"
var d, name //variables are defined outside function
func main() {
var i int //Variable is defined inside the function
fmt.Println(i, d, name)
}
How to initialize variables in Golang?
- If we assign a value to a variable then the variable will automatically take the type of initializer.
- If the value is not assigned then we need to add an initializer in Golang.
package main
import "fmt"
var i, j int = 1, 2 //Here variable i and j are initialized as integers
func main() {
var c, python, java = true, false, "no!" //Here there is no initialization done
fmt.Println(i, j, c, python, java)
}
Short Variable Declaration in Golang
- Inside a function in golang. The short assignment could be using:= symbol.
- Outside a function, we can not use short assignments as it is invalid.
package main
import "fmt"
func main() {
var i, j int = 1, 2
k := 3
c, name, language := true, false, "no!"
fmt.Println(i, j, k, c, name, language)
}
What are Zero Values in Golang?
- Variables that are defined without any initial value in Golang are known as Zero Value variables.
- For int type zero value is 0.
- For Boolean it is false.
- For strings it is "".
How to convert Type in Golang?
- Converting type in golang is very easy. You just have to write the variable inside the small brackets with the type. For eg,
var num_int int = 42
var num_float float64 = float64(i)
var num_u uint = uint(f)
Constants In Golang
- Constants in golang are created in the same way as variables but it starts with the const keyword
- Constants in go are created at the compile time. Even if they are defined in the functions they run at compile time.
- In golang constants can only be numbers, characters, strings, and booleans.
Example to Define a Constant
package main
import "fmt"
const Pi = 3.14
func main() {
const Name = "World"
fmt.Println("Hello", Name)
const Rank = 100
fmt.Println("Jee Rank = ", Rank)
const Bool_eg = true
fmt.Println("Output = ", Bool_eg)
}
