scala-while循环：带有`+=`的增量类型不匹配错误（found：Unit,required：Int）

Question

def merge(index: Int): Unit = {
    val len: Int = master.length + div(index).length
    var res = Array.ofDim[Long](len)
    var sign = Array.ofDim[Boolean](len)
    var i: Int = 0
    var j: Int = 0
    var resi: Int = 0
    while (i < master.length || j < div(index).length) {
      if (i == master.length) {
        res(resi) = div(index)(j)
        sign(resi += 1) = parity(index)(j += 1)
      }
      else if (j == div(index).length) {
        res(resi) = master(i)
        sign(resi += 1) = masterp(i += 1)
      }
      else if (master(i) < div(index)(j)) {
        res(resi) = master(i)
        sign(resi += 1) = masterp(i += 1)
      }
      else {
        res(resi) = div(index)(j)
        sign(resi += 1) = parity(index)(j += 1)
      }
    master = res
    masterp = sign
    }
  }

var j: Int = i
while (j >= 0) {
  div(index)(j + 1) = master(j) * p
  parity(index)(j + 1) = !masterp(j)
  j -= 1
}

提前感谢！

Answer 1

表达式x+=1返回一个单元，但这不是您所希望的。

如果要在x递增后返回，请使用

{ x += 1; x }

如在

sign({ resi += 1; resi }) = parity(index)({ j += 1; j })