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// Copyright 2012 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
import (
"fmt"
"math"
)
func InterfaceExample() {
var i interface{}
i = "a string"
i = 2011
i = 2.777
// STOP OMIT
r := i.(float64)
fmt.Println("the circle's area", math.Pi*r*r)
// STOP OMIT
switch v := i.(type) {
case int:
fmt.Println("twice i is", v*2)
case float64:
fmt.Println("the reciprocal of i is", 1/v)
case string:
h := len(v) / 2
fmt.Println("i swapped by halves is", v[h:]+v[:h])
default:
// i isn't one of the types above
}
// STOP OMIT
}
func main() {
InterfaceExample()
}
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