# Golang : Arithmetic operation with numerical slices or arrays example

Got an email from a new comer to Golang from South Africa, he or she wanted to know how to perform simple operations like arithmetic on numerical slices. There is a package - GoNum - that can do a better job for these kind of problems ... which I reckon is more efficient for mathematical calculations than using Golang's standard slices. However, there is no harm to use slices if all you wanted is to perform some simple operations like plus, minus, multiplication or division on slices or array.

Below is an example of how to use slices for arithmetic operations:

```
package main
import (
"fmt"
)
func main() {
a := []int{1, 2, 3, 4}
fmt.Println("Original : ", a)
// a * 2
for i, _ := range a {
a[i] = a[i] * 2
}
fmt.Println("a * 2 : ", a)
// a + 10
for i, _ := range a {
a[i] = a[i] + 10
}
fmt.Println("a + 10 : ", a)
b := []int{5, 6, 7, 8}
fmt.Println("b : ", b)
lengthOfA := len(a)
// will cause non-constant array bound lengthOfA error
//c := [lengthOfA]int{}
// if c size is constant, it is ok to hardcode with size of 4 (hand counted)
// c := [4]int{}
// or to make your program more robust
// figure out the slice c's length during runtime with length of a slice
c := make([]int, lengthOfA)
// a + b
// FOR a slice to plus b slice, the size or number of elements in both slices must be the same!
for i, _ := range a {
c[i] = a[i] + b[i]
}
fmt.Printf("a + b : %v + %v = %v \n", a, b, c)
d := make([]int, lengthOfA)
// a * b
for i, _ := range a {
d[i] = a[i] * b[i]
}
fmt.Printf("a * b : %v * %v = %v \n", a, b, d)
// use float64 instead of int type for division
e := make([]float64, lengthOfA)
// a / b
for i, _ := range a {
e[i] = float64(a[i]) / float64(b[i])
}
fmt.Printf("a / b : %v * %v = %v \n", a, b, e)
f := make([]int, lengthOfA)
// a - b
for i, _ := range a {
f[i] = a[i] - b[i]
}
fmt.Printf("a - b : %v * %v = %v \n", a, b, f)
}
```

Output:

Original : [1 2 3 4]

a * 2 : [2 4 6 8]

a + 10 : [12 14 16 18]

b : [5 6 7 8]

a + b : [12 14 16 18] + [5 6 7 8] = [17 20 23 26]

a * b : [12 14 16 18] * [5 6 7 8] = [60 84 112 144]

a / b : [12 14 16 18] * [5 6 7 8] = [2.4 2.3333333333333335 2.2857142857142856 2.25]

a - b : [12 14 16 18] * [5 6 7 8] = [7 8 9 10]

**References:**

https://socketloop.com/tutorials/golang-combine-slices-of-complex-numbers-and-operation-example

https://www.socketloop.com/tutorials/golang-squaring-elements-in-array

#### See also : Golang : Combine slices of complex numbers and operation example

##### By Adam Ng

IF you gain some knowledge or the information here solved your programming problem. Please consider donating to the less fortunate or some charities that you like. Apart from donation, planting trees, volunteering or reducing your carbon footprint will be great too.

#### Advertisement

#### Tutorials

+2.6k Golang : Derive cryptographic key from passwords with Argon2

+13.8k Golang : Get path name to current directory or folder

+29.4k Golang : Convert string to array/slice

+12.1k Golang : How to get hour, minute, second from time?

+2.9k Golang : Convert Chinese UTF8 characters to Pin Yin

+12.2k Golang : Count number of digits from given integer value

+7.3k Golang : Convert IP version 6 address to integer or decimal number

+14.6k Golang : Get password from console input without echo or masked

+26.4k Golang : How to check if slice or array is empty?

+16.9k Golang : Change file read or write permission example

+2.8k PHP : Convert CSV to JSON with YQL example

+3k Golang : How to transmit update file to client by HTTP request example