Go Function Parameters
Passing data to functions in Go
📥 What are Function Parameters?
Function parameters allow you to pass data into functions, making them flexible and reusable. Parameters act as variables that receive values when the function is called.
// Function with parameters
func greet(name string) {
fmt.Println("Hello,", name)
}
func main() {
greet("Alice") // Pass "Alice" as argument
}
Output:
Hello, Alice
Key Parameter Concepts
Declaration
Define parameters with name and type
func add(a int, b int) {
// a and b are parameters
}Arguments
Values passed when calling function
add(5, 3) // 5 and 3 are argumentsMultiple
Functions can have multiple parameters
func info(name string, age int) {
// Two parameters
}Types
Each parameter must have a type
func calc(x float64, y int) {
// Different types
}🔹 Single Parameter Functions
Functions with one parameter:
package main
import "fmt"
// Function with string parameter
func sayHello(name string) {
fmt.Println("Hello,", name)
}
// Function with integer parameter
func square(number int) {
result := number * number
fmt.Println("Square of", number, "is", result)
}
func main() {
sayHello("Bob")
square(4)
}Output:
Hello, Bob
Square of 4 is 16
🔹 Multiple Parameter Functions
Functions can accept multiple parameters:
package main
import "fmt"
// Function with multiple parameters
func add(a int, b int) int {
return a + b
}
// Function with different parameter types
func introduce(name string, age int, height float64) {
fmt.Printf("Name: %s, Age: %d, Height: %.1f\n", name, age, height)
}
func main() {
sum := add(10, 20)
fmt.Println("Sum:", sum)
introduce("Charlie", 25, 5.8)
}Output:
Sum: 30
Name: Charlie, Age: 25, Height: 5.8
🔹 Parameter Type Shorthand
When parameters have the same type, you can use shorthand:
package main
import "fmt"
// Long form
func multiply1(a int, b int, c int) int {
return a * b * c
}
// Short form - same type parameters
func multiply2(a, b, c int) int {
return a * b * c
}
// Mixed types
func calculate(x, y int, rate float64) float64 {
return float64(x+y) * rate
}
func main() {
result1 := multiply1(2, 3, 4)
result2 := multiply2(2, 3, 4)
result3 := calculate(10, 5, 1.5)
fmt.Println("Result 1:", result1)
fmt.Println("Result 2:", result2)
fmt.Println("Result 3:", result3)
}Output:
Result 1: 24
Result 2: 24
Result 3: 22.5