Convert float to int in Go (Golang)

Overview

Golang requires explicit conversion to convert from one type to the other. The float data type can directly be converted into float data type using explicit type conversion. Below is the syntax for that.

{destination_type}(some_value) 

This converts some_value to the destination type.

float64 to int

var a float64 = 12
var b int = int(a)

or

b := int(a)

Below is the program for the same

package main

import "fmt"

func main() {
    var a float64 = 12
    var b int = int(a)
    fmt.Printf("Underlying Type of b: %T\n", b)

    b2 := int(a)
    fmt.Printf("Underlying Type of b2: %T\n", b2)
}

Output

Underlying Type of b: int
Underlying Type of b2: int

float32 to int

var a float32 = 12
var b int = int(a)

or

b := int(a)

Below is the working program for the same. 

package main

import "fmt"

func main() {
    var a float32 = 12
    var b int = int(a)
    fmt.Printf("Underlying Type of b: %T\n", b)
    
    b2 := int(a)
    fmt.Printf("Underlying Type of b2: %T\n", b2)
}

Output

Underlying Type of b: int
Underlying Type of b2: int

In case, we directly assign a float value to an int variable without explicit conversion then it will raise the below compilation error. 

cannot use a (type float64) as type int in assignment

or

cannot use a (type float32) as type int in assignment

Also, check out our Golang advance tutorial Series – Golang Advance Tutorial