34 lines
761 B
Go
34 lines
761 B
Go
// Go supports _constants_ of character, string, boolean,
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// and numeric values.
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package main
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import "fmt"
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import "math"
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// `const` declares a constant value.
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const s string = "constant"
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func main() {
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fmt.Println(s)
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// A `const` statement can appear anywhere a `var`
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// statement can.
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const n = 500000000
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// Constant expressions perform arithmetic with
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// arbitrary precision.
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const d = 3e20 / n
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fmt.Println(d)
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// A numeric constant has no type until it's given
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// one, such as by an explicit conversion.
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fmt.Println(int64(d))
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// A number can be given a type by using it in a
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// context that requires one, such as a variable
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// assignment or function call. For example, here
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// `math.Sin` expects a `float64`.
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fmt.Println(math.Sin(n))
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}
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