42 lines
1.4 KiB
Go
42 lines
1.4 KiB
Go
package main
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import "fmt"
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func main() {
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// 基本类型转换
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var a int = 10
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var b float64 = float64(a) // 安全转换
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var c int = int(b + 0.9) // 丢失精度，c=10
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fmt.Printf("a=%d, b=%.1f, c=%d\n", a, b, c) // 输出a=10, b=10.0, c=10
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// 字符串与字节/符文切片转换
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s := "中文"
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bytes := []byte(s) // 转为字节切片（UTF-8编码，"中"占3字节）
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runes := []rune(s) // 转为符文切片（每个字符对应一个rune）
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fmt.Printf("s bytes: %x, s runes: %c\n", bytes, runes) // 输出s bytes: e4b8ade69687, s runes: [中 文]
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// 数组转切片
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arr := [3]int{1, 2, 3}
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slice := arr[:]
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fmt.Println("数组转切片:", slice) // 输出数组转切片: [1 2 3]
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// 接口类型断言（多值形式）
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var i interface{} = "hello"
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if str, ok := i.(string); ok {
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fmt.Printf("i is string: %s\n", str) // 输出i is string: hello
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} else if num, ok := i.(int); ok {
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fmt.Printf("i is int: %d\n", num)
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} else {
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fmt.Println("i is unknown type")
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}
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// 接口类型断言（单值形式，需确保类型正确）
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var j interface{} = 100
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num := j.(int)
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fmt.Printf("j is int: %d\n", num) // 输出j is int: 100
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// 错误示例（断言失败）
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str := j.(string) // 报错：panic: interface conversion: interface {} is int, not string
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fmt.Println(str)
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}
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