<p>Consider:</p>
<pre><code>type Maker interface {
Name() string
Type() string
}
type BallMaker interface {
R() int
Circ() int
}
type SquareMaker interface {
Width() int
Perimeter() int
}
</code></pre>
<p>If I want to check what my <code>Maker</code> is:</p>
<pre><code>if maker.Type() == ''BallMaker" {
//make balls
}
</code></pre>
<p>Or </p>
<pre><code>s, ok := maker.(SquareMaker)
if ok {
// make squares
}
</code></pre>
<p>Which one is idiomatic?</p>
<hr/>**评论：**<br/><br/>rdigel: <pre><p>I would always choose the type assertion. For one, there's no risk of mistyping the magic string.</p></pre>whizack: <pre><p>the short answer is that your question lacks sufficient context. neither are really idiomatic go because a problem like this would not be modeled as multiple interface types that don't satisfy the same interface.</p>
<p>taking a stab at an approximation of your problem, I'd consider doing something like this: <a href="https://play.golang.org/p/s9GPE3UId2N">https://play.golang.org/p/s9GPE3UId2N</a></p></pre>ui7_uy8: <pre><p>The answer is "it depends", really, especially when the compiler will restrict when you can use the second one.</p></pre>
