I'm trying to learn Go and I've created a function where I declare a variable game_ratio and set it to 0.0. I then have an if statement where I try and update the value of game_ratio. When I try and compile, I get the following error message: 'game_ratio declared and not used'
Here's my function:
func gameRatio(score1 int, score2 int, max_score float64) float64 {
var game_ratio float64 = 0.0
var scaled_score_1 = scaleScore(score1, max_score)
var scaled_score_2 = scaleScore(score2, max_score)
fmt.Printf("Scaled score for %v is %v
", score1, scaled_score_1)
fmt.Printf("Scaled score for %v is %v
", score2, scaled_score_2)
if score1 > score2 {
game_ratio := (scaled_score_1+1.0)/(scaled_score_1+scaled_score_2+2.0) + 1.0*0.5
}
return game_ratio
}
Here's the code to call it:
func main() {
flag.Parse()
s1 := flag.Arg(0)
s2 := flag.Arg(1)
i1, err := strconv.Atoi(s1)
i2, err := strconv.Atoi(s2)
if err != nil {
fmt.Println(err)
os.Exit(2)
}
fmt.Println("Game ratio is", gameRatio(i1, i2, 6))
}
ScaleScore is another function I have written. If I remove the if statement, the code works.
To run my app, I type 'rankings 28 24'
The short variable declaration is redeclaring game_ratio.
game_ratio := (scaled_score_1+1.0)/(scaled_score_1+scaled_score_2+2.0) + 1.0*0.5
Use an assignment. Write:
game_ratio = (scaled_score_1+1.0)/(scaled_score_1+scaled_score_2+2.0) + 1.0*0.5
The Go Programming Language Specification
A short variable declaration uses the syntax:
ShortVarDecl = IdentifierList ":=" ExpressionList .It is shorthand for a regular variable declaration with initializer expressions but no types:
"var" IdentifierList = ExpressionList .Unlike regular variable declarations, a short variable declaration may redeclare variables provided they were originally declared earlier in the same block with the same type, and at least one of the non-blank variables is new. As a consequence, redeclaration can only appear in a multi-variable short declaration. Redeclaration does not introduce a new variable; it just assigns a new value to the original.