将元组附加到 Scala 中的缓冲区 [英] Appending tuple to a buffer in Scala

问题描述

在 Scala 中，

test("Appending a tuple to a Buffer"){
    val buffer = ArrayBuffer[Int]()
    val aTuple = (2, 3)
    println(buffer += (2, 3))  // Result : ArrayBuffer(2, 3)
    println(buffer += aTuple )  // doesn't compile
}

为什么要行

println(buffer += (2, 3))  

工作，但行

println(buffer += aTuple ) 

不编译?

推荐答案

因为您没有添加 Tuple，所以您使用两个参数调用 += 方法:

Because you are not adding a Tuple, you are calling the += method with two parameters:

buffer += (3, 4)
// is equivalent here to
buffer.+=(3, 4)

该方法已定义 带和不带可变参数，并将其添加到缓冲区中:

And that method is defined both with varargs and without, and adds to the buffer everything it is given:

def +=(elem: A): ArrayBuffer.this.type 
def +=(elem1: A, elem2: A, elems: A*): ArrayBuffer.this.type 

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