go的匿名函数
<p>1、go的匿名函数，</p><div class="cnblogs_code">
<pre><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">匿名函数，就是函数不带函数名字呢！func(int)(int)
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">闭包通过匿名函数实现</span>
<span style="color: rgba(0, 0, 0, 1)">func OFFBag() {
a, str :</span>= <span style="color: rgba(128, 0, 128, 1)">10</span>, <span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">闭包</span><span style="color: rgba(128, 0, 0, 1)">"</span>
<span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">匿名函数定义，形成一个闭包，函数里面可以使用变量a和Str</span>
f1 := func() { <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">自动推导</span>
fmt.Println(<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">a= </span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">, a)
fmt.Println(</span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">str= </span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">, str)
}
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">调用f1()</span>
<span style="color: rgba(0, 0, 0, 1)"> f1()
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">第二种调用方式，少用</span>
type FuncType func() <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">定义函数类型</span>
<span style="color: rgba(0, 0, 255, 1)">var</span> f2 FuncType = f1 <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">声明变量</span>
<span style="color: rgba(0, 0, 0, 1)"> f2()
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">第三种调用方式，声明同时调用</span>
func() { <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">自动推导</span>
fmt.Println(<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">a= </span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">, a)
fmt.Println(</span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">str= </span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">, str)
}() </span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">圆括号代表调用匿名函数
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">带参数的匿名函数</span>
func(i, j int32) { <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">自动推导</span>
fmt.Println(<span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">i= </span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">, i)
fmt.Println(</span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">j= </span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">, j)
}(</span><span style="color: rgba(128, 0, 128, 1)">10</span>, <span style="color: rgba(128, 0, 128, 1)">20</span>) <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">圆括号代表调用匿名函数
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">有参数有返回值的匿名函数</span>
max, _ := func(i, j int32) (max, min int32) { <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">自动推导</span>
<span style="color: rgba(0, 0, 255, 1)">if</span> i ><span style="color: rgba(0, 0, 0, 1)"> j {
</span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> i, j
}
</span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> j, i
}(</span><span style="color: rgba(128, 0, 128, 1)">10</span>, <span style="color: rgba(128, 0, 128, 1)">20</span>) <span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">圆括号代表调用匿名函数</span>
<span style="color: rgba(0, 0, 0, 1)">
fmt.Println(</span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">max= </span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">, max)
}</span></pre>
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<p>2、闭包捕获外部变量，他不关心这些捕获的变量或常量是否超出作用域，所以只有闭包还在使用这些变量就会存在</p>
<div class="cnblogs_code">
<pre><span style="color: rgba(0, 0, 0, 1)">func main() {
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">声明并赋值变量</span>
str := <span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(128, 0, 0, 1)">闭包的特点</span><span style="color: rgba(128, 0, 0, 1)">"</span><span style="color: rgba(0, 0, 0, 1)">
fmt.Println(</span><span style="color: rgba(128, 0, 0, 1)">""</span><span style="color: rgba(0, 0, 0, 1)">, str)
f :</span>=<span style="color: rgba(0, 0, 0, 1)"> test1()
fmt.Println(f())
fmt.Println(f())
fmt.Println(f())
fmt.Println(f())
}
</span><span style="color: rgba(0, 128, 0, 1)">//</span><span style="color: rgba(0, 128, 0, 1)">函数的返回值是一个匿名函数，返回一个函数类型</span>
<span style="color: rgba(0, 0, 0, 1)">func test1() func() int32 {
</span><span style="color: rgba(0, 0, 255, 1)">var</span><span style="color: rgba(0, 0, 0, 1)"> x int32
</span><span style="color: rgba(0, 0, 255, 1)">return</span><span style="color: rgba(0, 0, 0, 1)"> func() int32 {
x</span>++
<span style="color: rgba(0, 0, 255, 1)">return</span> x *<span style="color: rgba(0, 0, 0, 1)"> x
}<br>输出结果：用来初始化一些全局变量<br><img src="https://img2020.cnblogs.com/blog/1429097/202004/1429097-20200401144339467-1362787914.png"></span></pre>
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<p>3、</p>
<p> </p><br><br>
来源：https://www.cnblogs.com/oceanran/p/12612878.html
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