为什么 fmt.Println(float64(1/2)) 显示 0？

Question

package main

import (
    "fmt"
)

func main() {
    fmt.Println(float64(1/2))
}

Why it prints: 0

Playground link: https://play.golang.org/p/KGgao6n8lTA

Is it because fmt.Println precision is low?

Answer 1

The order of operations here is: 1/2 = 0 (integer division truncates decimal places) followed by float64(0) = 0 , then fmt.Println(0) .

So in short: the integer division is truncated to 0. Everything else works fine.

As @Amadan commented, you can force a floating point division by casting one of the integers, ie float64(1) / 2 = 0.5 .