Mastering Golang: Type Casting

Golang Code Examples

Here’s how you can perform type casting in Go:

Basic Type Conversion:

You can perform type conversion by specifying the desired type in parentheses before the value you want to convert.

For example:

package main

import "fmt"

func main() {
    var x int = 42
    var y float64 = float64(x) // Convert int to float64
    fmt.Println(y)
}

Type Assertion (for interfaces):

Type assertion is used when you have an interface value and want to extract the underlying concrete type. It’s commonly used in Go when working with interfaces.

For example:

package main

import "fmt"

func main() {
    var i interface{} = 42
    // Check if i is an int and then convert it to an int
    if val, ok := i.(int); ok {
        fmt.Println(val)
    } else {
        fmt.Println("i is not an int")
    }
}

Type Switch (for interfaces):

Type switches are similar to type assertions but allow you to check the type of an interface value against multiple types.

For example:

package main

import "fmt"

func printType(i interface{}) {
    switch val := i.(type) {
    case int:
        fmt.Println("i is an int")
    case string:
        fmt.Println("i is a string")
    default:
        fmt.Printf("i is of type %T\n", val)
    }
}

func main() {
    var x int = 42
    var s string = "Hello"
    printType(x)
    printType(s)
}

These are the common ways to perform type casting and type checks in Go. Remember that type casting should be used carefully, as it can lead to runtime errors if the conversion is not valid. It’s important to check the compatibility of types before performing type casting.