如何在swift中使用for循环递减条件

Question

我可以通过以下代码在Swift中使用for in循环

   for i in 0..<5
{
    print ("Four multiplied by (i) results in (i*4)" )
}

但是如何使用小于">"条件的for呢

  for i in 10>..5
{
    print ("Four multiplied by (i) results in (i*4)" )
}

显示error: '>'不是后缀一元操作符

Answer 1

使用stride()方法:

for i in 10.stride(to: 5, by: -1) {
     print ("Four multiplied by (i) results in (i*4)" )
}

将递增到10、9、8、7和6。如果您希望包含5，请使用through:代替:

for i in 10.stride(through: 5, by: -1) {
     print ("Four multiplied by (i) results in (i*4)" )
}