使用strconv.ParseInt与ints的惯用方式

huangapple go评论70阅读模式
英文:

Idiomatic way to use strconv.ParseInt with ints

问题

我最终写出了这样的代码。我需要一个普通的int(用于其他函数调用),但是parseInt只能产生64位的int:

i64, err := strconv.ParseInt(s, 10, 0)
if err != nil {
	fmt.Println("解析失败:", s)
}
i := int(i64)

http://play.golang.org/p/_efRm7yp3o

有没有办法避免额外的类型转换?或者有没有办法使这个代码更符合惯用写法?

英文:

I end up writing code like this. I need a regular int (for some other function call), but parseInt only produces 64 bit ints:

i64, err := strconv.ParseInt(s, 10, 0)
if err != nil {
	fmt.Println("parsing failed for", s)
}
i := int(i64)

http://play.golang.org/p/_efRm7yp3o

Is there a way to avoid the extra cast? Or a way to make this more idiomatic?

答案1

得分: 3

你可以使用strconv.Atoi,它以你想要的方式包装了strconv.ParseInt

英文:

You can use strconv.Atoi which wraps strconv.ParseInt in a way you want.

答案2

得分: 0

使用strconv.ParseIntbitSize参数

package main

import (
        "fmt"
        "strconv"
)

// 32或64,取决于平台
const IntBits = 1 << (^uint(0)>>32&1 + ^uint(0)>>16&1 + ^uint(0)>>8&1 + 3)

func printInt(i int) {
        fmt.Println(i)
}

func main() {
        s := "-123123112323231231"
        i64, err := strconv.ParseInt(s, 10, IntBits)
        if err != nil {
                fmt.Println("解析失败:", s)
        }
        i := int(i64)
        printInt(i)

        i64, err = strconv.ParseInt(s, 10, 32)
        if err != nil {
                fmt.Println("解析失败:", s)
        }
        i = int(i64)
        printInt(i)
}

Playground


输出

-123123112323231231
解析失败: -123123112323231231
-2147483648
英文:

Use the bitSize parameter of strconv.ParseInt

package main

import (
        &quot;fmt&quot;
        &quot;strconv&quot;
)

// 32 or 64 depending on platform
const IntBits = 1 &lt;&lt; (^uint(0)&gt;&gt;32&amp;1 + ^uint(0)&gt;&gt;16&amp;1 + ^uint(0)&gt;&gt;8&amp;1 + 3)

func printInt(i int) {
        fmt.Println(i)
}

func main() {
        s := &quot;-123123112323231231&quot;
        i64, err := strconv.ParseInt(s, 10, IntBits)
        if err != nil {
                fmt.Println(&quot;parsing failed for &quot;, s)
        }
        i := int(i64)
        printInt(i)

        i64, err = strconv.ParseInt(s, 10, 32)
        if err != nil {
                fmt.Println(&quot;parsing failed for &quot;, s)
        }
        i = int(i64)
        printInt(i)
}

Playground


Output

-123123112323231231
parsing failed for  -123123112323231231
-2147483648

huangapple
  • 本文由 发表于 2013年7月16日 00:23:16
  • 转载请务必保留本文链接:https://go.coder-hub.com/17659021.html
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