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<h2 id="128-显示一个类型的方法集"><a class="header" href="#128-显示一个类型的方法集">12.8. 显示一个类型的方法集</a></h2>
<p>我们的最后一个例子是使用reflect.Type来打印任意值的类型和枚举它的方法</p>
<p><u><i>gopl.io/ch12/methods</i></u></p>
<pre><code class="language-Go">// Print prints the method set of the value x.
func Print(x interface{}) {
v := reflect.ValueOf(x)
t := v.Type()
fmt.Printf(&quot;type %s\n&quot;, t)
for i := 0; i &lt; v.NumMethod(); i++ {
methType := v.Method(i).Type()
fmt.Printf(&quot;func (%s) %s%s\n&quot;, t, t.Method(i).Name,
strings.TrimPrefix(methType.String(), &quot;func&quot;))
}
}
</code></pre>
<p>reflect.Type和reflect.Value都提供了一个Method方法。每次t.Method(i)调用将一个reflect.Method的实例对应一个用于描述一个方法的名称和类型的结构体。每次v.Method(i)方法调用都返回一个reflect.Value以表示对应的值§6.4也就是一个方法是绑到它的接收者的。使用reflect.Value.Call方法我们这里没有演示将可以调用一个Func类型的Value但是这个例子中只用到了它的类型。</p>
<p>这是属于time.Duration和<code>*strings.Replacer</code>两个类型的方法:</p>
<pre><code class="language-Go">methods.Print(time.Hour)
// Output:
// type time.Duration
// func (time.Duration) Hours() float64
// func (time.Duration) Minutes() float64
// func (time.Duration) Nanoseconds() int64
// func (time.Duration) Seconds() float64
// func (time.Duration) String() string
methods.Print(new(strings.Replacer))
// Output:
// type *strings.Replacer
// func (*strings.Replacer) Replace(string) string
// func (*strings.Replacer) WriteString(io.Writer, string) (int, error)
</code></pre>
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