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This article mainly explains "how to understand the performance of Scala loops". The content of the explanation is simple and clear, and it is easy to learn and understand. please follow the editor's train of thought to study and learn "how to understand the performance of Scala loops".

Recently I was learning the code for our product and saw a code similar to the following:

X.set (1) x.set (2) x.set (3) x.set (4) x.set (5)

I was very confused at that time, why not cycle? So I signed up for an Issue, thinking that it might make sense, but I needed to clarify it.

Another problem is that I found that there are different ways to use loops in the code, some people write array.foreach (f = > _), some people use for loop using index, personally, I think the code using foreach is relatively simple, so I also reported Issue to see if we should use a concise way to write loops. For example:

For loop

Var index = 0 var arr = Array [String] var length = arr.length for (index Unit, num: Int, name: String): Unit = {val tStart = System.currentTimeMillis () (0 until num) .foreach {_ = > f} val tEnd = System.currentTimeMillis () println (name + "took" + (tEnd-tStart) + "ms")} def main (args:Array [String]) {test (whileLoop, 50000000, "whileLoop") test (repeatLoop, 50000000) "repeatLoop")}}

After 50000000 cycles, the data are as follows:

WhileLoop took 281ms repeatLoop took 47ms

Indeed, because of the extra overhead of loop control logic, the performance is much lower than that of simple repetitive code.

Thank you for reading, the above is the content of "how to understand the performance of Scala cycle". After the study of this article, I believe you have a deeper understanding of how to understand the performance of Scala cycle, and the specific use needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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