为什么我要 make() 或 new()? [英] Why would I make() or new()?

问题描述

介绍文档用了很多段落来解释new()和make()之间的区别，但在实践中，您可以在本地范围内创建对象并返回它们.

The introduction documents dedicate many paragraphs to explaining the difference between new() and make(), but in practice, you can create objects within local scope and return them.

为什么要使用这对分配器?

Why would you use the pair of allocators?

推荐答案

Go 有多种内存分配和值初始化的方式:

Go has multiple ways of memory allocation and value initialization:

&T{...}、&someLocalVar、new、make

创建复合文字时也可能发生分配.

Allocation can also happen when creating composite literals.

new 可用于分配整数等值，&int 是非法的:

new can be used to allocate values such as integers, &int is illegal:

new(Point)
&Point{}      // OK
&Point{2, 3}  // Combines allocation and initialization

new(int)
&int          // Illegal

// Works, but it is less convenient to write than new(int)
var i int
&i

new 和 make 的区别可以看下面的例子:

The difference between new and make can be seen by looking at the following example:

p := new(chan int)   // p has type: *chan int
c := make(chan int)  // c has type: chan int

假设 Go 没有 new 和 make，但它有内置函数 NEW.然后示例代码将如下所示:

Suppose Go does not have new and make, but it has the built-in function NEW. Then the example code would look like this:

p := NEW(*chan int)  // * is mandatory
c := NEW(chan int)

* 将是强制性的，所以:

new(int)        -->  NEW(*int)
new(Point)      -->  NEW(*Point)
new(chan int)   -->  NEW(*chan int)
make([]int, 10) -->  NEW([]int, 10)

new(Point)  // Illegal
new(int)    // Illegal

是的，可以将 new 和 make 合并为一个内置函数.然而，与拥有两个内置函数相比，一个单一的内置函数可能会导致新的 Go 程序员更加困惑.

Yes, merging new and make into a single built-in function is possible. However, it is probable that a single built-in function would lead to more confusion among new Go programmers than having two built-in functions.

考虑到以上所有几点，new 和 make 保持分开似乎更合适.

Considering all of the above points, it appears more appropriate for new and make to remain separate.

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