Operators

Go's operators look familiar from almost any C-family language, but Go is far stricter about mixing types than most of them — nothing gets silently converted for you.

Arithmetic operators

Go main.go

package main

import "fmt"

func main() {
	a, b := 17, 5

	fmt.Println(a + b)
	fmt.Println(a - b)
	fmt.Println(a * b)
	fmt.Println(a / b)
	fmt.Println(a % b)
}

Output

a, b := 17, 5 declares two variables in one line, both inferred as int. a / b prints 3, not 3.4 — dividing two integers in Go always produces an integer result, truncating any remainder, which a % b then recovers.

Note: Go has no implicit numeric conversion at all — not even between int and float64. Writing 17 / 5.0 with a mix of an int variable and a float64 literal is a compile error; you have to convert explicitly with float64(a) / 5.0. This is more strict than C, C++, C#, or Java, all of which will happily promote an int to a floating-point type for you.

Comparison and logical operators

Go main.go

package main

import "fmt"

func main() {
	age := 20
	hasTicket := true

	fmt.Println(age >= 18)
	fmt.Println(age >= 18 && hasTicket)
	fmt.Println(age < 18 || !hasTicket)
}

Output

true
true
false

>=, <, and friends all return a plain bool. && (and) and || (or) short-circuit exactly like in C, C++, JavaScript, and most other languages here — the right side of && is never evaluated if the left side is already false.

Explicit type conversion

Go main.go

package main

import "fmt"

func main() {
	total := 17
	count := 5

	average := float64(total) / float64(count)
	fmt.Println(average)
}

Output

3.4

float64(total) converts total's value to a float64 without changing what total itself is — the conversion produces a new value, and division between two float64s does the real division you'd expect.

PreviousVariables & Data Types NextConditionals