blocks|key|540383|text|fmt.SprintF函数返回一个字符串，您可以使用与fmt.PrintF相同的方式设置字符串的格式|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|540384|entityMap^0|0|B|R|A|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|M|8|@]|D|@]|E|$]]]|G|$]]

<code>fmt.SprintF</code> function returns a string and you can format the string the very same way you would have with <code>fmt.PrintF</code>

blocks|key|323565|text|我们可以通过支持Format的define+new+Type自定义一个新的字符串类型。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|323566|package+main

import+(
++++"fmt"
++++"text/template"
++++"strings"
)

type+String+string
func+(s+String)+Format(data+map[string]interface{})+(out+string,+err+error)+{
++++t+:=+template.Must(template.New("").Parse(string(s)))
++++builder+:=+&strings.Builder{}
++++if+err+=+t.Execute(builder,+data);+err+!=+nil+{
++++++++return
++++}
++++out+=+builder.String()
++++return
}


func+main()+{
++++const+tmpl+=+`Hi+{{.Name}}!++{{range+$i,+$r+:=+.Roles}}{{if+$i}},+{{end}}{{.}}{{end}}`
++++data+:=+map[string]interface{}{
++++++++"Name":+++++"Bob",
++++++++"Roles":++++[]string{"dbteam",+"uiteam",+"tester"},
++++}

++++s+,_:=+String(tmpl).Format(data)
++++fmt.Println(s)
}|code-block|syntax|javascript|323567|注意：{{.}}代表{{range+$i,+$r+:=+.Roles}}+{{.}}+{{end}}中的{{$r}}|323568|entityMap^0|8|6|F|F|0|0|3|5|A|14|1G|6|0^^$0|@$1|2|3|4|5|6|7|O|8|@$9|P|A|Q|B|C]|$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]|$9|Z|A|10|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|N|$]]

We can custom A new String type via <code>define new Type</code> with <code>Format</code> support.
<pre><code>package main

import (
 &quot;fmt&quot;
 &quot;text/template&quot;
 &quot;strings&quot;
)

type String string
func (s String) Format(data map[string]interface{}) (out string, err error) {
 t := template.Must(template.New(&quot;&quot;).Parse(string(s)))
 builder := &amp;strings.Builder{}
 if err = t.Execute(builder, data); err != nil {
 return
 }
 out = builder.String()
 return
}


func main() {
 const tmpl = `Hi {{.Name}}! {{range $i, $r := .Roles}}{{if $i}}, {{end}}{{.}}{{end}}`
 data := map[string]interface{}{
 &quot;Name&quot;: &quot;Bob&quot;,
 &quot;Roles&quot;: []string{&quot;dbteam&quot;, &quot;uiteam&quot;, &quot;tester&quot;},
 }

 s ,_:= String(tmpl).Format(data)
 fmt.Println(s)
}
</code></pre>
Note: <code>{{.}}</code> represent <code>{{$r}}</code> in <code>{{range $i, $r := .Roles}} {{.}} {{end}}</code>

blocks|key|323636|text|我来到这个页面是为了寻找一种格式化错误字符串的方法。因此，如果有人在这方面需要帮助，您可以使用fmt.Errorf()函数。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|323637|方法签名为func+Errorf(format+string,+a+...interface{})+error。它将格式化后的字符串作为满足error接口的值返回。|323638|您可以在文档-+https://golang.org/pkg/fmt/#Errorf中查找更多详细信息。|323639|entityMap|0|LINK|mutability|MUTABLE|url|https://golang.org/pkg/fmt/#Errorf^0|1B|C|0|5|1E|1Y|5|0|8|Y|0|0^^$0|@$1|2|3|4|5|6|7|R|8|@$9|S|A|T|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|Z|8|@]|D|@$9|10|A|11|1|12]]|E|$]]|$1|J|3|-4|5|6|7|13|8|@]|D|@]|E|$]]]|K|$L|$5|M|N|O|E|$P|Q]]]]

I came to this page specifically looking for a way to format an error string. So if someone needs help with the same, you want to use the <code>fmt.Errorf()</code> function.
The method signature is <code>func Errorf(format string, a ...interface{}) error</code>.
It returns the formatted string as a value that satisfies the <code>error</code> interface.
You can look up more details in the documentation - <a href="https://golang.org/pkg/fmt/#Errorf" rel="nofollow noreferrer">https://golang.org/pkg/fmt/#Errorf</a>.

blocks|key|323689|text|尝试使用Sprintf()；它不会打印输出，但会保存输出以供将来使用。看看这个。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|323690|package+main

import+"fmt"

func+main()+{
++++
++++address+:=+"NYC"

++++fmt.Sprintf("I+live+in+%25v",+address)

}|code-block|syntax|javascript|323691|当您运行此代码时，它将不会输出任何内容。但是，一旦您将Sprintf()分配给一个单独的变量，它就可以用于将来的用途。|323692|package+main

import+"fmt"

func+main()+{
++++
++++address+:=+"NYC"

++++fmt.Sprintf("I+live+in+%25v",+address)

++++var+city+=+fmt.Sprintf("lives+in+%25v",+address)
++++fmt.Println("Michael",city)

}|323693|entityMap^0|4|9|0|0|R|9|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@$9|V|A|W|B|C]]|D|@]|E|$]]|$1|M|3|N|5|H|7|X|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|Y|8|@]|D|@]|E|$]]]|P|$]]

try using <code>Sprintf()</code>; it will not print the output but save it for future purpose.
check this out.
<pre><code>package main

import &quot;fmt&quot;

func main() {
 
 address := &quot;NYC&quot;

 fmt.Sprintf(&quot;I live in %v&quot;, address)

}
</code></pre>
when you run this code, it will not output anything. But once you assigned the <code>Sprintf()</code> to a separate variable, it can be used for future purposes.
<pre><code>package main

import &quot;fmt&quot;

func main() {
 
 address := &quot;NYC&quot;

 fmt.Sprintf(&quot;I live in %v&quot;, address)

 var city = fmt.Sprintf(&quot;lives in %v&quot;, address)
 fmt.Println(&quot;Michael&quot;,city)

}
</code></pre>

blocks|key|323712|text|您可以将new内置与template.Template一起使用，而不是使用template.New|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|323713|package+main

import+(
+++"strings"
+++"text/template"
)

func+format(s+string,+v+interface{})+string+{
+++t,+b+:=+new(template.Template),+new(strings.Builder)
+++template.Must(t.Parse(s)).Execute(b,+v)
+++return+b.String()
}

func+main()+{
+++bar+:=+"bar"
+++println(format("foo:+{{.}}",+bar))
+++i+:=+25
+++println(format("foo:+{{.}}",+i))
}|code-block|syntax|javascript|323714|entityMap|0|LINK|mutability|MUTABLE|url|//pkg.go.dev/text/template#Template^0|4|3|11|C|A|H|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|G|5|H|7|10|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

Instead of using <code>template.New</code>, you can just use the <code>new</code> builtin with
<a href="//pkg.go.dev/text/template#Template" rel="nofollow noreferrer">template.Template</a>:
<pre><code>package main

import (
 &quot;strings&quot;
 &quot;text/template&quot;
)

func format(s string, v interface{}) string {
 t, b := new(template.Template), new(strings.Builder)
 template.Must(t.Parse(s)).Execute(b, v)
 return b.String()
}

func main() {
 bar := &quot;bar&quot;
 println(format(&quot;foo: {{.}}&quot;, bar))
 i := 25
 println(format(&quot;foo: {{.}}&quot;, i))
}
</code></pre>

Is there a simple way to format a string in Go without printing the string?

I can do:

<pre><code>bar := "bar"
fmt.Printf("foo: %s", bar)
</code></pre>

But I want the formatted string returned rather than printed so I can manipulate it further.

I could also do something like:

<pre><code>s := "foo: " + bar
</code></pre>

But this becomes difficult to read when the format string is complex, and cumbersome when one or many of the parts aren't strings and have to be converted first, like

<pre><code>i := 25
s := "foo: " + strconv.Itoa(i)
</code></pre>

Is there a simpler way to do this?

Format a Go string without printing?

有没有一种简单的方法可以在Go中格式化字符串而不打印字符串？我可以这样做：bar := "bar"fmt.Printf("foo: %s", bar)但是我希望返回格式化后的字符串，而不是打印出来，这样我就可以进一步操作它。我也可以这样做：s := "foo: " + bar但是，当格式字符串很复杂时，这就变得很难阅读...

问在不打印的情况下格式化Go字符串？
EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问在不打印的情况下格式化Go字符串？EN

社区

活动

资源

关于

腾讯云开发者

热门产品

热门推荐

更多推荐

问在不打印的情况下格式化Go字符串？
EN